Khao Piak Sen (Lao Chicken Noodle Soup) Recipe

A dish loaded with slippery noodles, layers of aromatics, and an abundance of fresh and fragrant toppings.

A bowl of khao piak sen (Lao chicken noodle soup).

Serious Eats / Liz Clayman

Why It Works

  • Using the oil from the fried garlic and shallots to make the broth captures every ounce of flavor.
  • Optionally charring some of the onion and ginger adds depth and complexity to the broth.
  • Using a stand mixer to start the noodles protects your hands from the heat of the boiling water.
  • Cooking the noodles in the broth adds starch to the broth itself, giving it its signature viscosity.

The first time I encountered khao piak sen, or Lao chicken noodle soup, was through a TV screen. Chef James Syhabout of Oakland’s Commis and San Francisco’s Hawker Fare was face-deep in a bowl as he told Anthony Bourdain about his relationship with Laos, a country he and his family fled in the 1970s. There was something so raw about the scene—Chef Syhabout slurping the soup almost hurriedly, as if he’s chasing a memory; him tipping back the bowl for its last remnants; sitting quietly for a moment after he’s done—I immediately decided I needed a bowl for myself.

After a frenzy of Googling, I managed to track down just one restaurant offering khao piak sen in New York City: Hug Esan, a northeastern Thai (Isan) restaurant in the Elmhurst neighborhood of Queens. The bowl there, while absolutely delicious, left me with even more questions than before. Why was the broth made from pork, not chicken? Are these the same noodles as the Vietnamese bánh canh (a similarly thick, soft noodle made of tapioca and rice flour)? Why is a Lao dish being served at a Thai restaurant? And why am I growing so obsessed with this soup?

With so many points to resolve, I put out queries for Lao experts and was serendipitously introduced to Chef Seng Luangrath of Washington D.C.’s Thip Khao. Like Chef Syhabout, she also fled Laos as a child during the Vietnam War (which raged in Laos as a "secret war"), finding refuge first in Thailand before resettling in the U.S.

Now an active champion of the Lao Food Movement, Chef Luangrath was more than willing to educate me about one of her best-selling soups. She told me that khao piak sen translates as "wet rice noodle" and is a chicken (and sometimes pork) broth–based soup filled with shredded poached chicken, translucent rice-and-tapioca noodles, and topped with a bounty of fresh herbs.

A collage showing aromatics for khao piak sen broth: charred onion in one photo, plus the pot full of chopped lemongrass, plus lime leaves and more to make the broth for khao piak sen.
Aromatics like charred onion, lemongrass, and makrut lime leaves are popular options for khao piak sen.

Serious Eats / Liz Clayman

Within a few minutes of our call, Chef Luangrath sighed with great tenderness and said, “It’s a noodle I remember really well; a noodle I just love so much.” At its core, it’s a soup about personalization. “The best part is that everyone makes it how they like to eat it,” Chef Luangrath told me. “My broth is a simple one made with ginger, others like it with lemongrass, or with galangal and [makrut] lime leaves. Some char the vegetables [like onion and garlic] or add cilantro stems. Some make it with pork neck bones instead of the whole chicken.”

While many aspects of the soup are open to interpretation, its hallmark texture—glossy and slightly viscous—remains intact across many versions. This comes from the act of cooking raw noodles directly in the broth once the chicken has been removed, letting the starch add body to the broth.

“Some people will even put extra starch in, while others will rinse out the flour because they want a clearer broth,” Chef Luangrath explained. However the final bowl arrives, it is always served with fresh vegetables and condiments, a signature of Lao cuisine. The classics are scallion, cilantro, chile oil, fried garlic, fried shallot, lime wedges, black pepper, and white pepper, but there’s plenty of room for improvisation with fresh bean sprouts or curly twines of morning glory.

Rows and rows of khao piak sen vendors are a frequent sight in the Lao capital city of Vientiane, something Chef Luangrath remembers quite fondly. “My neighbors would make this soup early in the morning and bring it to the market. Every mall would have a khao piak sen stall.” Beyond a breakfast favorite, it’s also a popular late-night (“after parties”) snack, as well as a frequent item at important gatherings (it’s common for mourners to eat a bowl together at the end of funerals, before the body is cremated).

Khao piak sen is a dish that showcases the multiculturalism inherent in Lao history and its people. Ethnic Lao trace their ancestors to a group of people speaking a common “Tai” language who once lived in Southern China. They moved southward in a series of migrations—differing historical theories place this time period anywhere from the 8th to the 12th century CE—and settled in the area that is modern day Laos, northeastern Thailand (Isan region), and adjacent parts of Vietnam.

This makes a lot of sense given the soup's curious commonalities with aspects of Chinese cuisine: after she learned I’m Chinese-American, Chef Luangrath excitedly told me there’s khao piak sen vendors that will serve a steaming bowl with youtiao, a long fried doughnut stick that’s common to eat alongside congee or soy milk for breakfast in certain parts of China.

As a food that encourages personalization, khao piak sen has fittingly endured as a centerpiece of the Lao diaspora. “Many Thai restaurants [in D.C. and beyond] will sneak khao piak sen on the menu, or on the secret menu—that’s how I know [the restaurant is] probably Lao-owned,” Chef Luangrath tells me with a small laugh. The relationship between Thai and Lao people is complicated, in part because of the blurring of ethnic and country lines, as those born or raised in northeastern Thailand but who are ethnically Lao have experienced sweeping erasure of Laotian influence—including the use of “Lao” as a descriptor, replacing it with “northeastern Thai” or “Isan”—at the hands of the Thai government.

After a military coup in the 1930s, the new Thai leaders led a nationalist “Thaification” campaign aimed to "unify" the country and prioritize Thai people, culture, and language over the peoples, cultures, and languages of Lao, Chinese, and Malay populations. (This was also the time pad thai was introduced as the de facto national dish.)

As a result, some of Laos’ biggest culinary contributions, such as larb (sometimes written as laap), som tam, and the plentiful pockets of sticky rice served alongside a meal, have been introduced in the US as purely regional Thai cuisine. Lao cooks offering khao piak sen in some of these restaurants, then, can be seen as a quiet form of asserting their identities—as Chef Syhabout put it, now “it’s a matter of re-educating."

Attempting to distill khao piak sen down to just one version, when its very nature is to be colorful and varied, was a challenge in and of itself. Chef Luangrath generously sent me both her broth and noodle recipes, from which I built a foundational flavor profile. A few chickens later, I found myself craving more heft in the broth, and played around with charring some portion of the onion and ginger until I landed at what tasted like the sweet spot to me. This additional body then needed some brighter notes for balance, which fresh cilantro stems and makrut lime leaves did perfectly.

Bags of rice flour and tapioca flour; they will be used to make the slippery noodles for Lao soup khao piak sen.
The noodles for khao piak sen are made with tapioca and rice flours; the exact ratio changes the final texture.

Serious Eats / Liz Clayman

Noodle-wise, I struggled. The most common ratio for these fresh noodles is 1:1 rice flour to tapioca flour, but for those who prefer a chewier noodle, many recipes online recommend a 1:1.5 or a 1:1.3 rice-to-tapioca ratio. “Some also put salt or MSG in the base,” Chef Luangrath told me. She occasionally adds some baking soda to give the noodles a springier bite, which follows in the same line of reasoning as making a simplified ramen by adding an alkaline ingredient (note this does give the noodles a slightly yellow color).

While the ratios were difficult enough to navigate, the main issue I ran into was the actual technique for making the noodles. I used my trusty stand mixer to mix the flours and the hot water—the key term here being "hot," as in boiling, to activate the starch—but once mixed together they became impossibly sticky to work with.

Naturally, the videos of Chef Luangrath making noodles seemed effortless in comparison (she often does the whole sequence by hand in a large metal bowl, undeterred by the water temperature). Eventually I landed on a method that yielded reliable results, even with my rather weak wrists and the fact that my hands can't withstand 212°F (100°C) water, adding more of each flour during the kneading step to give the final dough a pliable, but not overly wet, consistency. As for the debate over ratios, I liked the softness of the rice flour and found any formulation with more than the 1:1 ratio rather hard to chew—but that’s completely up to the cook.

As Chef Luangrath and I finished up our call, she told me a little anecdote about how Lao food is finally, rightfully, beginning to find its own space in the American food vernacular. “I used to always have to explain [khao piak sen] as similar to udon, or bánh canh, but now people are learning what it is, coming back and asking for it.” I could tell she was beaming on her side of the phone, and that seemed fitting. Beyond offering more than a little bit of comfort in a bowl, khao piak sen is an intimate dish that reminds us how closely food is tied to identity. Little wonder, then, that Chef Luangrath would find some reaffirmation when others discover how delicious it can be.

Overhead shot of Laotian chicken noodle soup with accompaniments.

Serious Eats / Liz Clayman

October 2019

Recipe Facts

Prep: 15 mins
Cook: 3 hrs
Active: 3 hrs 30 mins
Total: 3 hrs 15 mins
Serves: 8 servings

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Ingredients

For the Fried Garlic and Shallot:

  • 1 cup (240ml) vegetable oil

  • 24 cloves garlic (120g), sliced thinly crosswise, preferably with a mandoline

  • 3 medium shallots (150g), sliced thinly crosswise into rounds, preferably with a mandoline

For the Broth and Chicken:

  • 1 medium yellow onion (10 ounces; 280g), peeled and quartered through the root end

  • 3 large knobs ginger (3 ounces; 90g), peeled and sliced crosswise into 1/4 inch thick rounds

  • 3 tablespoons (45ml) garlic and shallot oil, from above

  • 1 stalk lemongrass (2 3/4 ounces; 80g), outer layer discarded then roughly chopped

  • 6 medium cloves garlic (1 ounce; 30g), peeled and thinly sliced crosswise

  • 5 makrut lime leaves

  • Stems from 1 bunch cilantro (2 ounces; 60g), chopped (see notes)

  • One 3- to 4-pound (1.3 to 1.8kg) whole chicken, blotted dry (see notes)

  • 2 tablespoons kosher salt (3/4 ounce; 25g), plus more as needed

  • 2 tablespoons soy sauce (1 ounce; 30g)

  • 2 tablespoons Asian fish sauce (1 ounce; 30g)

  • 1 teaspoon sugar

For the Noodles:

  • 7 ounces (200g) plus 3/4 ounce (20g) white rice flour, divided (see notes)

  • 7 ounces (200g) plus 3/4 ounces (20g) tapioca flour, divided

  • 1 3/4 cups (415ml) boiling water

To Finish and Serve the Soup:

  • 2 scallions, sliced thinly on the bias

  • 2 fresh bird’s eye chiles, stemmed and minced

  • 5 sprigs morning glory, pulled through a morning glory shredder (optional; see notes)

  • Lime wedges

  • Fried garlic, from above

  • Fried shallots, from above

  • Picked cilantro leaves and tender stems

Directions

  1. For the Fried Garlic and Shallot: Line a plate with paper towels and set a fine-mesh strainer over a medium heatproof bowl. In a medium frying pan, heat oil over medium heat until shimmering. Add garlic and fry, swirling and stirring frequently, until golden brown all over, approximately 4 minutes. Pour garlic and oil into prepared strainer and allow to drain. Transfer garlic to the prepared paper towels, spreading it out in an even layer, and allow to drain further.

  2. Return oil to pan, then set fine-mesh strainer over the same heatproof bowl. Line a second plate with clean paper towels.

  3. Add shallots to pan and cook over high heat, stirring frequently, until shallots begin to bubble, about 1 minute. Continue cooking, stirring constantly as the shallots fry to ensure even cooking, until shallots turn pale golden brown, about 3 minutes longer. Working quickly, pour contents of saucepan into strainer set over bowl. (Shallots will continue cooking for a brief period after draining, so do not allow them to get too dark.) Reserve garlic-shallot oil.

  4. For the Broth and Chicken: If desired, grill or sear (in a cast iron pan without oil) two of the onion quarters and two-thirds of the sliced ginger until well charred, about 2 minutes per cut side (this will add depth and complexity to the broth, but is optional).

    Charred onion on grill for khao piak sen.

    Serious Eats / Liz Clayman

  5. Roughly chop all of the onion and ginger, whether charred or not.

  6. In a large 8-quart Dutch oven or soup pot, heat garlic-shallot oil over medium heat until shimmering. Add chopped onion and ginger, lemongrass, sliced garlic, lime leaves, and cilantro stems. Season lightly with salt, then cook, stirring, until onions are softened, about 7 minutes.

    Sauteing lemongrass, makrut lime leaves, onions, garlic, and ginger for khao piak sen broth.

    Serious Eats / Liz Clayman

  7. Add chicken to pot and top with at least 5 quarts (5L) cold water, or enough to cover. Add the 2 tablespoons kosher salt along with the soy sauce, fish sauce, and sugar. Bring to a simmer, then lower heat to maintain a gentle simmer. Cook, covered, for 2 hours, lifting lid occasionally to skim the surface of broth of any foam or scum that accumulates.

    A collage: adding chicken to the sauteed aromatics, followed by water and seasoning to the broth.

    Serious Eats / Liz Clayman

  8. Carefully remove chicken from the pot and transfer to a work surface (it may fall apart after this long cooking; simply fish out all the parts and bones). When cool enough to handle, pull meat from bones and shred with your hands or a fork. Discard bones and skin. Reserve chicken meat.

    A collage: removing chicken from the broth and shredding the meat with a fork.

    Serious Eats / Liz Clayman

  9. Meanwhile, bring broth to a rolling boil and cook, uncovered, for 30 minutes. Strain broth, discarding solids, then return to cleaned pot. Season with salt.

  10. For the Noodles: While the broth simmers, make the noodles. In a stand mixer fitted with the dough hook, add 7 ounces rice flour and 7 ounces tapioca flour. Turn mixer to medium-low speed and drizzle in boiling water. Continue to mix, pausing occasionally to scrape down the sides with a flexible spatula, until a moist dough ball forms, about 3 minutes.

    A collage of making the dough for khao piak sen noodles.

    Serious Eats / Liz Clayman

  11. Whisk together remaining rice and tapioca flours, then sprinkle on a work surface. Turn dough ball out onto floured work surface. Knead dough by hand until all of the flour on the board has been fully incorporated into a supple dough, about 4 minutes.

  12. Roll dough into a thick log and divide into 8 equal portions. Roll each portion into a small ball, then flatten with the palm of your hand.

    Stages of kneading and portioning dough for khao piak sen noodles into balls, pressing the dough flat.
  13. Working one dough disc at a time, and keeping the remainder covered with a kitchen towel to prevent drying, roll using a rolling pin until roughly 1/8 inch thick and about 6 inches long.

    A collage of rolling the dough and forming noodles for khao piak sen.
  14. Using a sharp knife, slice into noodles roughly 1/4 inch wide. Transfer to a rimmed baking sheet, dusting and tossing gently with rice flour to prevent sticking. Keep noodles covered with a damp towel so they don’t dry out. Repeat with remaining dough.

  15. To Finish and Serve the Soup: Add noodles to boiling finished broth and cook, stirring very minimally to prevent them from breaking (they're brittle until they cook through), until noodles float to the surface, 1 to 2 minutes.

    Adding raw noodles to broth for khao piak sen.

    Serious Eats / Liz Clayman

  16. Transfer noodles to soup bowls. Add shredded chicken to each bowl. Ladle broth into bowls. Serve hot, allowing diners to garnish their soup with scallions, chiles, morning glory (if using), lime, fried garlic, fried shallots, and cilantro leaves and tender stems.

Notes

If you can find it, you can also use cilantro roots. An old hen, if you can find it, works well in this recipe; otherwise, any whole chicken will be good.

This recipe uses finely milled white rice flour, commonly found in Asian grocery stores. These are different than those available at most chain grocery stores, such as Bob’s Red Mill, because the finer rice flour is much more absorbent. If you are using a brand such as Bob’s Red Mill, add an additional 30g of rice flour to the original mixture and increase the amount of both rice flour and tapioca flour for the second step of the kneading process to 50g.

Morning glory, also known as water spinach, can be found at Asian markets.

Special Equipment

Stand mixer, scale, fine-mesh strainer, 8-quart Dutch oven or soup pot, morning glory shredder (optional)

Make-Ahead and Storage

The fried garlic and shallots and the broth can be made up to five days in advance; refrigerate the broth until ready to use, and keep the fried garlic and shallots in airtight containers at room temperature.

The noodles can be frozen for up to one month: To freeze, arrange in thin, even layers on parchment on a rimmed baking sheet, stacking more parchment between each layer; wrap well in plastic, then freeze. To cook frozen noodles, place directly into boiling broth without thawing and let cook 1 to 2 minutes longer than fresh noodles until they float to the surface.

Nutrition Facts (per serving)
450 Calories
13g Fat
55g Carbs
29g Protein
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Nutrition Facts
Servings: 8
Amount per serving
Calories 450
% Daily Value*
Total Fat 13g 17%
Saturated Fat 3g 14%
Cholesterol 121mg 40%
Sodium 1956mg 85%
Total Carbohydrate 55g 20%
Dietary Fiber 2g 8%
Total Sugars 4g
Protein 29g
Vitamin C 11mg 53%
Calcium 70mg 5%
Iron 3mg 18%
Potassium 504mg 11%
*The % Daily Value (DV) tells you how much a nutrient in a food serving contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.
(Nutrition information is calculated using an ingredient database and should be considered an estimate.)