Khao soi is the Northern Thai noodle dish that combines curry broth, boiled noodles, and crispy fried noodles.
The best-known Thai version uses wheat-and-egg noodles in a rich curry soup, often made with coconut milk. A serving commonly includes boiled noodles in the broth and a separate portion of crisp fried noodles on top. Lime, pickled mustard greens, shallots, and chili relish are frequent accompaniments.
Khao soi is strongly associated with Chiang Mai and northern Thailand, although related versions are found across parts of mainland Southeast Asia. Its history reflects the movement of Muslim Chinese traders and noodle traditions through the region.
Khao soi is sometimes confused with khanom chin, which uses fermented rice noodles and is served with different curry preparations. The spelling and recipes also vary, but the contrasting soft and crunchy noodles are the signature feature of the common Chiang Mai style.