West Lake fish in vinegar gravy. [Photo/CFP]

The delicacy xihu cu yu, which literally translates to "West Lake fish in vinegar gravy", is a cherished dish of Zhejiang province.

The fish used in the dish is often grass carp. There is even an ancient story behind it, which can be traced all the way back to the Song Dynasty (960-1279).

Xihu cu yu was also called "songsao yu," literally meaning "sister-in-law song fish." During the Song Dynasty, there were two knowledgeable brothers from the Song family. They lived near West Lake in Hangzhou, Zhejiang and made a living by fishing. One day, the elder brother was killed due to persecution. His wife and younger brother pleaded with local government officials for justice but ended up being given the brush-off. Later, the younger brother was forced into exile for safety. Before he departed, the sister-in-law cooked a fish with sugar and vinegar for him, implying "do not forget the sour amidst the sweet." She hoped that the younger brother would do better in the future. The dish she made is the so-called "West Lake fish in vinegar gravy."