Choy Sum Recipe: How to Cook Chinese Choy Sum

Choy sum is a leafy green vegetable that’s part of the Brassica genus of the mustard family. Choy sum greens are picked when they are young and tender, and look very similar to Chinese broccoli but with smaller, more tender stems. The texture is somewhere between baby bok choy and Chinese broccoli. Cooks often blanch choy sum and serve it as a side dish with garlic sauce or oyster sauce, add it to soups or noodle dishes, or sautée it in a wok with a weeknight stir-fry.

In Cantonese, “choy sum” means “heart of the plant” and can technically be used to refer to any tender baby Chinese greens. Choy sum is also called yu choy (which refers to this plant in particular), Chinese flowering cabbage, or Chinese oil vegetable.

Choy sum or yu choy, bok choy, and gai lan are leafy greens in the Brassica family popular in Chinese cuisine. Cooks often prepare these Asian greens similarly, though they vary in levels of bitterness and texture. When you cook with Chinese greens, keep these differences in mind:

• Yu choy: “Yu choy” translates to “oil vegetable.” It’s also known as yu choy sum, yao choy, yau choy, and Chinese oil vegetable. This vegetable has dark green leaves and thin pale stems dotted with small, bright yellow flowers. Yu choy is one of the sweetest Chinese greens. Cooks typically blanch and stir-fry yu choy.
• Choy sum: Choy sum, which means “heart of the vegetable,” refers to the tender stems of the yu choy plant, or more rarely, any tender Chinese greens. The words “choy sum” and “yu choy” are used interchangeably and usually mean the same thing. Choy sum is sweet, and cooks often blanch and serve it as a side dish or add it to soups.
• Bok choy: Bok choy, also known as white cabbage, is a variety of Chinese cabbage with dark green leaves and thick white stalks. Its name means “white vegetable” in Cantonese. Bok choy is closely related to turnips, broccoli rabe, napa cabbage, tatsoi, and mizuna. With origins in Central Asia, bok choy is one of the oldest cultivated vegetables. In American supermarkets, two main varieties of bok choy are common: "regular" bok choy, which has a ruffly dark green leaf and bright white stems, and Shanghai bok choy, which has smooth, oval leaves and is light green from the leaves to the stalk.
• Gai lan: Gai lan, or Chinese broccoli, is a leafy vegetable also known as Chinese kale or kai lan. The flavor is similar to broccoli but stronger and slightly bitter. Compared to broccoli, the stalks are thinner, longer, and more tender, and the florets feature small yellow flowers. Sturdier vegetables like gai lan can stand up to the longer cooking time in braising.