Khao Soi: Northern Thai Red Curry Noodle Soup

Khao soi is one of those dishes that you fall in love with the first time you try it. The history is long and involved, but at the heart of it, khao soi is a dish that is uniquely Thai, born from several imports and morphed by Thai cooks to make it better. It started up in Northern Thailand, and spread nationwide (although the experts insist that any version not made in Chiang Mai is an inferior imposter).

The dish was introduced by ‘Cin-Haw' (Chin-Haw) Muslim traders from Yunnan. Han Chinese called the Cin-Haw ‘Hui' to distinguish them from non-Muslim Chinese; ‘Cin Haw' are the Thai words for ‘Chinese Hui'. The Cin were originally descendants of Uzbek warriors who were brought by the Mongols into China to help with the conquest of Yunnan province. They were known as consummate traders, who for hundreds of years regularly plied their heavily-armed mule caravans over the trade routes from Southern China into Laos, Northern Thailand, and, eventually Burma. The Cin-Haw population in Northern Thailand and Burma further increased after the failed Panthay Rebellion - an uprising against the Yunanese Qing Dynasty, which caused refugees to flee Yunnan.

Several factors reinforce this Cin-Haw likelihood. There is a somewhat similar dish eaten in Burma, known there as ohn no khauk-hswe (khauk-hswe, which is phonetically pronounced similar to khao soi, and simply means ‘noodles' in Burmese). This may account for the adopted name of the dish in Thailand. The Burmese dish is similarly spiced, and uses coconut milk in the broth (an unusual trait for Burma), but is thickened with chickpea flour, a decidedly Indian cooking method.

Another vaguely similar version exists in Malaysia and extreme Southern Thailand, known as nonya laksa lemak , a coconut milk and seafood broth with egg noodles, served with prawns, a garnish of thinly sliced egg omelet, scallion, and ginger (lemak refers to the presence of coconut milk). The dish is thought to have been introduced in the South by Haw Sino-Muslim traders or refugees, who later interacted with the Nonya: ethnic Chinese who resettled and intermarried into Malaysia and Singapore culture.

Perhaps the best evidence of the origin of khao soi come from the statements of the founder of Chiang Mai's famous Lamduan Faham Khao Soi , which has been serving the dish on Faham Road for more than 60 years (Faham is known as Khao Soi Road). The founder, who is now in her advanced years, says that she was taught the recipe by some Haw Chinese Muslim immigrants who relocated during the war, first to the area near the town of Fang, and then to Chiang Mai, “It was the Haw Chinese that showed me how to make the distinctive yellow noodles, as well as the soup.” Lamduan altered that original recipe so that it would appeal more to the Thai palette, but the dish was eaten for many years before that, all over the North. It is important to note that the dish was originally cooked only with chicken or beef, never with pork, which also reinforces the Muslim origins. Today, some non-Muslim Thais offer the soup made with pork, but this is an anomaly which is not typical.

Khao soi is sold up north in noodle shops that specialize in the dish; traditionally they were open from morning to the early afternoon only. The shops are usually unassuming affairs, with modest signage. It's a word-of-mouth type of dish, and insider information is key to finding the best versions. One of the pleasures of khao soi is that no two noodle shops or vendors will serve exactly the same dish; every cook has their own subtle variation, and every khao soi aficionado has their favorite venue for dining on the luscious noodle soup. Arguments over who serves the best version can get heated, and everyone has a personal opinion.

Often khao soi shops will also serve chicken, beef, or pork satay (pork only if they are non-Muslim), skewers of spice and coconut milk-marinated meats, grilled over coals, and served with toasted white bread, and a peanut curry sauce and a sweet-sour relish of shallot, cucumber, and chiles. In the rest of the country, specialty khao soi shops and vendors exist, but the popularity of the dish causes it to be included on many standard noodle restaurant menus.

When a bowl of khao soi is placed in front of you, your senses take over; it's a work of culinary art. Visually you'll see a subtle reddish-orange colored liquid, topped with golden-yellow fried noodles, garnished with pinkish-red shallots, light green pickled Chinese mustard, and deep red chile. It's fragrant with the aromas of combined Thai and Indian spices, coconut milk, chicken broth, citrusy lime, and smoky chile. The taste is ambrosial: rich, spicy, sweet, salty, and sour, all at once, and in perfect harmony.

Our favorite version, like the one served at Sap’s Fine Thai Cuisine (shown here), is made with a base of rich chicken stock, to which thick coconut milk is added. You can get it with either chicken meat or stewed beef meat, although these days, pork is also offered. The spices are a blend of a paste made from garlic, shallot, galangal, lemongrass, makroot zest and fruit pulp, with a small amount of shrimp paste and palm sugar. To this paste are added bay leaf, curry powder, cumin, coriander, black pepper, and turmeric.

Fresh dan mien Chinese egg noodles, lo mein-style, which are flat and about ¼-inch wide (a little more narrow than a fettuccine) are added to the liquid. These same noodles are also deep-fried until golden and crispy, and placed on the top to provide a textural accent. Before indulging, you must garnish the bowl with the accompanying sliced shallot or red onion, slices of sour and salty pickled mustard, a vigorous squeeze of tart lime, and a spoonful of the smoky chile sauce made from roasted red Thai chiles. Sap's version garnishes with fresh, crisp mung bean sprouts, and places the pickled Chinese mustard in the bottom of the bowl; an addition that we like.

A bowl of excellent khao soi is hard to beat, a synchronous blending of Thai, Indian, and Chinese flavors, in a rich and sensual broth, with complex layered flavor and interesting texture. It is truly perfection in a bowl, ideal for sultry or cool weather, and uniquely Thai in flavor profile.

Mick Vann © Wonk in Progress