Chongqing. Sauerkraut fish, also known as fish in sour soup, is a classic dish originating from the city of Chongqing, known for its characteristic seasoning and unique cooking techniques. Popularized in the 1990s, it is one of the trailblazers of Chongqing's Jianghu cuisine. Sauerkraut is made with grass carp as the main ingredient, cooked with pickles and other ingredients, and tastes hot and sour, the fish is rich in high-quality protein, and the lactic acid in the sauerkraut promotes the body's absorption of iron, and also increases one's appetite. A pot of steaming hot pickled fish are tender white fish fillets, red spicy oil, petite sesame seeds, deep emerald-colored sauerkraut. One taste and the freshness and spiciness is just right.