In Thailand, kao soi is made with ba mee, a variety of egg noodles, that can be difficult to find in the U.S. But lo mein-style Chinese egg noodles are a good substitute.
- 4 cups vegetable oil
- 3⁄4 lb. fresh lo mein-style egg noodles
- 1 Tbsp. Thai red pepper (coarsely ground) or cayenne pepper
- 3 Tbsp. Thai red curry paste
- 1 Tbsp. Madras-style curry powder
- 1 tsp. ground cumin
- 2 1⁄4 cups unsweetened coconut milk
- 1 1⁄2 cups chicken stock
- 2 Tbsp. nam pla (Thai fish sauce)
- 1 tsp. sugar
- 1 lb. boneless chicken breast, cut in 2''–3'' pieces
- 3-4 scallions, white parts only, chopped
- 2 shallots, peeled and quartered
- 1⁄3 cup pickled cabbage, rinsed and julienned
- 2 limes, halved
Heat about 3 1⁄2 cups oil in a wok over medium-high heat. Add a large handful of noodles and cook until crisp, about 1 minute. Remove noodles immediately and drain on paper towels. Pour off frying oil (which can be reused 2–3 times; strain and store in a closed container until needed), wipe out wok, then add 2 tbsp. fresh oil. Heat over medium-high heat, then add red pepper and fry, stirring constantly, until oil begins to smoke, about 30 seconds. Remove from heat and stir in enough remaining oil, about 3 tbsp., to form a thick chile oil. Transfer to a small bowl and set aside.
Wipe out wok, then add curry paste, curry powder, and cumin, and cook, stirring, over medium-high heat until fragrant, about 40 seconds. Stir in coconut milk and stock and bring to a boil. Reduce heat to medium, add nam pla and sugar, and simmer, stirring occasionally, for 5 minutes. Stir in chicken and simmer until chicken is cooked through, about 5 minutes more. (Add up to 1 cup of water if soup is too thick.)
Cook remaining noodles by blanching in a large pot of boiling water until soft, about 1 minute. Drain, then refresh under cold water.
Divide noodles among 4 soup bowls, ladle soup into bowls, and top with scallions and fried noodles. Serve with shallots, pickled cabbage, chile oil, and limes.