Choi Sum

This is the most familiar spelling for this vegetable, though its first character is often spelled choy or tsoi when romanized into Cantonese. The leafy vegetables with thin stalks are all green, from their large outer leaves to their smaller inside leaves to their light green stalks. The stalks, after their hard ends are trimmed, are crisp and sweet. Choi sum, like other leafy vegetables, tends to lose its sweetness as it ages. Its leaves become yellow and it sprouts small yellow flowers, so eat it as fresh as possible. It will keep for no more than 2 days in the vegetable drawer of a refrigerator.