The dish is believed to have evolved from Chinese Muslim traders who plied the spice route when what is now modern-day northern Thailand was controlled by the Burmese.[4]
Lao khao soi is traditionally made with hand-sliced rice noodles in clear broth and topped with minced pork.[5] In some markets in Luang Namtha and Muang Sing, vendors still hand-cut the noodles. These traditionally cut noodles can also be found in several places in northern Thailand.
Lao khao soi is completely different and has no relation to the more famous Muslim-influenced khao soi, a rich coconut curry and egg rice noodle soup, of northern Thailand and Burma.[5]Lao khao soi is a hand-sliced rice noodle soup with clear chicken, beef or pork broth topped with a tomato meat sauce made of minced pork, tomatoes, garlic, and fermented bean paste.[6] The dish is always served with fresh herbs. Lao khao soi noodles are made with steamed rectangular sheets of rice flour batter. The streamed rice flour sheets are then rolled and sliced into wide rice noodle ribbons. The name khao soi is derived from the Lao language meaning 'sliced rice': khao is “rice” and soimeans “sliced” and it is probably where the dish got its name. The northern Lao provinces of Luang Namtha and Luang Prabang are said to be the birthplace of the Lao khao soi.[7][8] Northern Laotians have a special way of preparing this dish; different versions of it can be found at Lao restaurants.[9]
Khao soi - BangkokKhow SueyNorthern Thai khao soi or Khao Soi Islam is closer to the present-day Burmese ohn no khao swè, being a soup-like dish made with a mix of deep-fried crispy egg noodles and boiled egg noodles, pickled mustard greens, shallots, lime, ground chillies fried in oil, and meat in a curry-like sauce containing coconut milk.[10] The curry is somewhat similar to that of yellow or massaman curry but of a thinner consistency. It is popular as a street dish eaten by Thai people in northern Thailand, though not frequently served in Thai restaurants abroad. The Northern Thai khao soi's predecessor was likely a noodle dish that made its way to the region from Myanmar, via the Chin Haw, a group of Thai Chinese Muslims from Yunnan, who traded along caravan routes through Shan State in Myanmar, Laos, and Thailand from the 18th to early 20th centuries.[11] Due to the Muslim influence, the noodle soup was originally halal, and therefore commonly served with chicken or beef, not pork.[12][11] Different variants of khao soi that are made without any coconut milk and with rice noodles instead of egg noodles are mainly eaten in the eastern half of northern Thailand.
Chicken khao soi with curdled blood in a school cafeteria, Chiang Rai, Thailand.
Khao soi Mae Sai, with (minced) pork and curdled blood, is a Thai variant that does not contain coconut milk or curry but uses the same sauce as in nam ngiao.
A Muslim style khao soi nuea (beef khao soi), Chiang Mai, Thailand.
Khao soi nam na is a style of khao soi with a minced pork-and-chilli paste, that is eaten in the eastern part of Chiang Rai Province, Thailand.
Khao soi noi songkhrueang is a Shan dish: a wrap made from steamed rice flour batter with a filling of steamed vegetables and dusted with ground peanuts.
^"Kao Soi". Lao Food Recipes. The Boat Landing Guest House and Restaurant. 26 March 2010. Archived from the original on 16 July 2012. Retrieved 7 July 2012.