Khao Piak Sen Is Lao-Style Chicken Noodle Soup With Soul

A bowl of Lao noodle soup khao piak sen, piled with garnishes like fresh cilantro, scallions, fried garlic, and more; additional condiments are in the background

[Photographs: Liz Clayman]

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?

Adding the chicken, water, salt, and soy sauce to a pot to make the broth for khao piak sen

Khao piak sen broth made with chicken and flavorings like salt and soy sauce; some recipes use pork as well.

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.

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.

Adding a handful of the starchy noodles to a pot of simmering khao piak sen broth

Cooking the starchy noodles in the broth gives khao piak sen's broth its hallmark viscosity.

“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, chili 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 soymilk 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.

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.

Making khao piak sen dough in a stand mixer: boiling water is added, then the sough is worked with the dough hook until it comes together

While experienced cooks can do the entire process by hand, a stand mixer makes it easier to initially incorporate the boiling water into the flours.

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 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.

Making khao piak sen noodles by hand: rolling the dough, cutting it into thick strips, piling them up on a baking sheet well tossed with flour to prevent sticking

After starting the dough in a stand mixer, it is finished by hand; the noodles are cut by hand as well.

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.

A bowl of Lao noodle soup khao piak sen, seen from above and piled with garnishes like fresh cilantro, scallions, fried garlic, and more