Oxtail Khao Soi Recipe. A Lao Tai Lue Fermented Bean Tomato Meat Sauce Noodle Soup. This is also shared and made within the Iu Mien, Lahu, and many Sub Group Cultures of Laos. Each Culture has their own take. There are Many Versions of Khao Soi throughout Southeast Asia. For those who never had this. The Flavors are Savory, Rich in Flavors once you add all the Condiments. Wide Rice Noodles are Chewy Bouncy. You get Ground Pork that hangs on to the Noodle Strands per Bite. The Fermented Bean Past