The best-known Chinese vegetable, bok choy, literally “white vegetable” because of its white bulbous stalk, is grown throughout China and other parts of Asia. Its crispness and inherent sweetness make it particularly versatile. Although often referred to as Chinese cabbage, the vegetable’s deep green leaves above a white stalk bear no resemblance to a cabbage. Bok choy comes in various sizes, from as long as 15 to 18 inches to as small as 2 to 3 inches. There are even bok choy sprouts. They are all the same vegetable, and the size of the head dictates how it is used, whether as a primary ingredient or as a garnish. Bok choy will keep for 2 days in the vegetable drawer of a refrigerator. Kept longer, its leaves gradually turn yellow and its flavor diminishes, so use it at its freshest.