Kow Soi (Thai Khao Soi) Recipe: Authentic Thai Curry Noodle Soup

By Rachael Lake — Founder of Takeout Kit (Forbes, TechCrunch, BuzzFeed)

This Thai khao soi recipe (also known as kow soi) is Northern Thailand's curry noodle soup: tender egg noodles in a coconut curry broth, with a nest of crispy fried noodles on top.

What is Khao Soi?

Khao soi (or kow soi) is a Northern Thai noodle soup. The broth is red curry made creamy with coconut milk, and the bowl gets two kinds of noodles: soft egg noodles in the soup and crispy fried ones on top. A dash of fish sauce and a little sugar season it.

Khao soi originated in northern Thailand's Chiang Mai province, though its roots trace back to the Chin Haw - Chinese Muslim traders who brought egg noodle soups over the Burmese border in the late 19th century. The dish evolved as it absorbed Thai flavors: coconut milk replaced the original clear broth, and Thai curry paste replaced Chinese five-spice. Today, khao soi is the signature dish of Chiang Mai, where it's served at virtually every street stall and night market. The Burmese version (ohn no khao swè) and the Lao version (khao soi Lao, which confusingly uses rice noodles in a meat sauce) are distinctly different dishes despite sharing the name.

What khao soi tastes like

Khao soi is sweet, sour, and spicy at once. It comes out of centuries of trade between Burma and Yunnan, China, and you can taste that in the bowl: kaffir lime, pickled mustard greens, lemongrass, shallots, chiles, and red curry paste. That mix is what separates it from similar soups like laksa.

What makes khao soi unique among Thai curries is its dual-noodle technique: soft egg noodles swim in the coconut curry broth while a nest of deep-fried crispy egg noodles crowns the bowl. The crispy noodles serve both as a textural contrast and as edible utensils for scooping the rich sauce. Authentic khao soi paste includes dried red chilies, turmeric, coriander, shallots, garlic, ginger, and shrimp paste - similar to yellow curry paste but with more turmeric, which gives the broth its characteristic golden color. In Chiang Mai, every cook has their own paste recipe, and the ratio of turmeric to chili determines whether a khao soi leans mellow-golden or fiery-red.

Essential Ingredients

Recipes for kow soi vary, but these are the basics:

• Egg noodles: Fresh or dried. Some get boiled for the soup and some get fried crisp for the top.
• Coconut milk: Makes the broth creamy and softens the heat of the spices.
• Curry paste: The base of the broth, and the thing that makes it taste like khao soi.
• Protein: Commonly chicken, beef, or pork-braised until tender in the curry broth.
• Aromatics: Onions, garlic, and shallots for the base of the broth.
• Spices: Warm spices like star anise, cinnamon, and cardamom.

Preparing the Curry Paste

Store-bought curry paste works, but making your own gets you closer to the real thing. Toast and grind coriander seeds, cumin, and cinnamon, then grind in garlic, ginger, turmeric, paprika, and cayenne pepper. Season it with a splash of fish sauce and a pinch of sugar.

Ingredients:

• 2 tablespoons coriander seeds
• 1 tablespoon cumin seeds
• 1 tablespoon cinnamon sticks
• 2 cloves garlic, minced
• 1 small onion, minced
• 2 tablespoons grated ginger
• 1 tablespoon turmeric powder
• 1 tablespoon paprika
• ½ teaspoon cayenne pepper
• Salt, to taste
• 2 tablespoons vegetable oil

Instructions:

1. Dry roast the coriander, cumin, and cinnamon in a pan over medium heat until fragrant.
2. Grind the roasted spices into a fine powder using a spice grinder or mortar and pestle.
3. Add the garlic, onion, ginger, turmeric, paprika, cayenne, and salt. Grind until a smooth paste forms.
4. Heat the vegetable oil in a pan over medium heat and cook the paste for 1-2 minutes, stirring constantly until fragrant.

Tips, variations, and an Instant Pot version

Tips and Variations

Here are some ideas to personalize your Kow Soi/Khao Soi:

• Adjust the Heat: Modify the chili or cayenne pepper levels to suit your spice tolerance.
• Protein Options: Tofu, seafood, or other meats all work.
• Noodle Varieties: While egg noodles are traditional, try rice or glass noodles for a twist.
• Use medium high heat to sauté spices without burning them.

Instant Pot Khao Soi (Pressure-Cooked Chicken)

For a quicker version, the Instant Pot cooks the chicken under pressure right in the coconut broth. Finish with a squeeze of lime and a drizzle of fish sauce.

Ingredients:

• 1 tablespoon curry paste
• 2 cups coconut milk
• 1 cup chicken broth
• ½ cup water
• 1 tablespoon fish sauce
• 1 tablespoon brown sugar
• ½ teaspoon salt
• ¼ teaspoon black pepper
• 1 lb chicken thighs or drumsticks
• Aromatics:
  • 1 small onion, chopped
  • 2 cloves garlic, minced
  • 1 shallot, sliced
• 2 cups egg noodles
• Fresh herbs (cilantro, basil, or mint) for garnish

Instructions:

Sauté Aromatics:
Press the "Sauté" button on your Instant Pot. Add a splash of oil and sauté the chopped onion, garlic, and shallot until softened (about 2-3 minutes).

Develop the Curry Paste:
Add the curry paste to the pot and continue to sauté for another 1-2 minutes until it becomes fragrant.

Build the Broth:
Stir in the coconut milk, chicken broth, and water. Then add the fish sauce, brown sugar, salt, and black pepper.

Pressure Cook the Chicken:
Place the chicken thighs or drumsticks into the pot, ensuring they are mostly submerged in the liquid. Cancel the Sauté mode, secure the Instant Pot lid, and set it to Pressure Cook (Manual) on high for 10 minutes.

Release Pressure:
Once the cooking cycle finishes, allow a natural pressure release for 5 minutes, then carefully quick-release any remaining pressure.

Shred the Chicken:
Remove the chicken from the pot. Shred or chop it into bite-sized pieces and return it to the broth.

Cook the Noodles:
Switch the Instant Pot back to Sauté mode. Add the egg noodles and cook for about 2 minutes, stirring gently until they are just tender.

Finish & Serve:
Taste the broth and adjust the seasoning if necessary. Ladle the soup into bowls, garnish with fresh herbs (and a squeeze of lime if desired), and serve hot.

More Thai recipes

For more, browse my Thai Recipes section, or try the Thai Pumpkin Curry and Thai Crab Curry. For quality ingredients, try Thai Supermarket.

More Thai curries: My Thai Green Curry (gaeng khiao wan) uses a two-stage coconut cream technique and is ready in 30 minutes.

The traditional khao soi condiment plate is as important as the soup itself: pickled mustard greens (phak kat dong), sliced shallots, a lime wedge, and roasted chili paste (nam prik pao). The pickled greens cut through the richness of the coconut broth, while the raw shallots add sharp bite. In Chiang Mai, you'll also see diners adding a spoonful of the roasted chili paste directly into the broth for extra depth. Chicken thighs (bone-in for maximum flavor) are the most traditional protein, though beef khao soi is common in Muslim neighborhoods of Chiang Mai's old city.