酸菜鱼 originated in Chongqing/Sichuan in the 1980s and rode the chain-restaurant boom (
太二,
鱼你在一起) into a nationwide staple. The fish is typically grass carp (
草鱼) sliced thin; the sourness comes from fermented mustard greens, the heat from pickled chilies and Sichuan peppercorns.
