This is a shredded, salted, preserved cabbage that is crunchy and keenly aromatic. The cabbage is called winter cabbage and is grown primarily in the area around Tientsin, south of Peking, hence the Chinese name is quite specifically “Tientsin winter cabbage,” though the translation on the label is confusingly vague. To add to the confusion, the dish in which this condiment is best known is Dry-Fried Szechwan String Beans.
The brand I like best is widely distributed, marketed in an attractive, squat crock with a rich brown glaze. There is a red, white, and blue label over the mouth of the crock and also a banner on the side that has nothing in English save the words Tientsin Preserved Vegetables. In traditional style, the crock is sealed with a heavy paper “lid,” which must be cut through and then pulled off. To store the cabbage, simply seal the crock with a square or two of tin foil held in place with a thick rubber band, then keep it at room temperature away from light, heat, and moisture. It will keep forever, like any respectable preserved vegetable.