Hot and sour soup is a popular example of Chinese cuisine. Although it is said to be originated in Sichuan, this is actually a variant of hulatang or "pepper hot soup" (胡辣汤) with added vinegar to enhance the sourness. This variation is found in Henan province, and in Henan cuisine itself.[1][2][3] Also popular in Southeast Asia, India, Pakistan and the United States, it is a flexible soup which allows ingredients to be substituted or added depending on availability. For example, the American-Chinese version can be thicker as it commonly includes corn starch, whilst in Japan, sake is often added.
