Suan cai is a type of Chinese pickled vegetable, primarily made from fermented mustard greens. This traditional dish is popular in various regions of China, especially in the north. The fermentation process gives Suan cai its distinctive sour flavor, making it a versatile ingredient in many dishes, such as soups and stir-fries. Typically, Suan cai is prepared by salting the greens and allowing them to ferment for several days to weeks. The result is a tangy, crunchy condiment that can enhance the taste of meals. It is often enjoyed with rice or noodles, adding a unique flavor profile to the cuisine.