A member of the bok choy/Chinese cabbage family, tat soi has dark green, puckered leaves. The plant's stems are small, pale-green to white and Swiss chard-like Tatsoi's flavor profile is reminiscent of cabbage, with a juicy, chewy texture. It is delicious in salads and frequently appears in the better mesclun mixes. If you steam or stir-fry the leaves, they become more tender and milder in flavor.