This recipe is by chef Lek Trirattanavatin from Ponsonby's Saan: "Khao soi means hand-cut rice noodle in Thai, because original flat egg noodles contain rice flour. It is a true traditional northern region (Lanna) dish, which was influenced by the Chin Haws (Chinese Muslim people who migrated to Thailand
via Burma). The dish is a blend of Chinese, Middle Eastern and Southeast Asian. It is very rare to find khao soi in any other part of Thailand, but it's commonly found in the North, especially in Chiang Mai. My mother is originally from the Phichit Province, Northern Region, and she passed on the family's khao soi recipe to me. It is a very unique one. Phichit Province produces the best quality rice and therefore they have the best khao soi flat egg noodles. Traditionally, khao soi can be made with beef or chicken, but some people do use pork or sai ua sausage for this dish."