There are two varieties of Chinese leaf vegetables, Napa cabbage and bok choy, that are related to turnips and fall into the same genus as cabbage, broccoli and cauliflower. Bok choy, from Cantonese and literally meaning “white vegetable”, is called pak choi in the UK, Australia, South Africa and other Commonwealth nations. Less often you may find it referred to as Chinese chard, Chinese mustard, celery mustard or spoon cabbage.
The Chinese have been cultivating bok choy for more than 5,000 years. It was mainly grown in the Yangtze River Delta region until Ming Dynasty naturalist Li Shizen popularized it by describing its medicinal benefits (we now recognize that it’s packed with vitamins A and C). Around the 14th century, bok choy from Zhejiang was brought north (possibly because it’s winter hardy) and soon the northern harvest exceeded that of the south. The vegetables then returned south along the Grand Canal to Hangzhou and were traded by sea as far south as Guangdong. Although bok choy was introduced to Europe in the 1800s and has been commercially grown in the United States for more than 100 years (California, Florida, Hawaii and New Jersey are the main growing states), other cuisines have been slow to embrace it. It remains firmly associated with Chinese cooking.
Bok choy does not form heads. Instead, smooth, glossy, dark green, spoon-shaped leaves form a cluster similar to mustard or celery. It is particularly popular in southern China and Southeast Asia, where as many as twenty varieties are available, including Shanghai bok choy, much prized for its light green color and sweet, crisp leaves. Martin Yan, host of television’s Chinese cooking show Yan Can Cook, has pointed out that Asia doesn’t share America’s conviction that bigger is better, especially in regards vegetables. In China, baby bok choy and other smaller vegetables are valued for their tenderness. And baby bok choy has the added advantage of being cooked whole or halved, reducing preparation effort and time.
Look for bok choy with firm, bright green leaves and moist, firm stems. Avoid browned, yellowed or wilted leaves and any with small holes, which might suggest insect infestation. While it is available throughout the year, bok choy season peaks from mid winter through early spring. Store it in a plastic bag in the refrigerator for up to one week and don’t wash it until you’re ready to use it.
The recipes that follow call for baby bok choy but, if that is not available, regular bok choy can be substituted. Separate the leaves from the stalks and wash thoroughly in cold water. Drain and cut the stems, on the diagonal, into 1-inch pieces. Cut the leaves separately into 1 inch pieces. Stir fry the stems for 1 minute, add the leaves and stir fry for a minute longer. Pour in the chicken stock or water, cover the wok and cook over medium heat for about 2 minutes, or until the stems are translucent. Do not overcook; the stalks should be tender and the leaves just wilted.