Choy sum.

Choy sum is a leafy green with slim, juicy stems, smooth leaves and, often, a few small yellow flowers at the tips. The flowers are meant to be there and you cook them along with the rest. It tastes mild and a little sweet, with less bite than Chinese kale, and it softens in a minute or two. In Thailand it's one of the most common greens of all. Growers sow it in almost every month, and it turns up in stir fries, noodle soups and clear broths at home and on the street.

Ways to use it

• Stir fry with garlic and oyster sauce over high heat, just until the stems turn bright green.
• Cut into short lengths and add to rad na or a bowl of noodle soup in the last minute.
• Blanch whole stems, then drizzle with a little oil and soy sauce.
• Drop into a clear soup with minced pork or tofu near the end.
• Toss into fried rice or pad see ew for colour and crunch.

Storing it

Keep the bunch unwashed in a container lined with paper towels, in the fridge drawer, and try to use it within a day or two. Leafy greens like this go limp quickly. Wash the stems under running water just before cooking, and check the base of the leaves where soil can hide.

Where it comes from

Grown to certified organic standards. The certificate for each lot is shown when you trace your pack.

Every pack will carry a lot code. Enter it on the Trace your pack page and you will see the farms in that lot, the harvest date and the certificate.