Many have been introduced to bok choy by their local Chinese restaurant; it is a type of cabbage, but looks more like the love child of celery and romaine. It is an excellent source of vitamin C and vitamin A, and a good source of folate. Look for heads with deep green, glossy leaves and bright white stalks; brown areas can mean they were stored poorly and may have lost flavor. Baby bok choy can be cooked whole; older bok choy can be chopped before cooking. Tear the leaves from the stalks, slice the stalks crosswise, and cut the leaves coarsely. Bok choy can be used in salads, or it can be steamed, braised, sautéed or stir-fried.