Komatsuna

Brassica rapa var. pervirdis
Often known as mustard spinach, its leaves are tender and mild. It can be used as a cut-and-come-again crop at any stage of growth. Use steamed or stir-fried or in salads and soups. Komatsuna is a traditional ingredient in Japanese cooking. It features excellent bolt resistance and cold tolerance so can be grown all year round.
Matures in 21 days. (open pollinated seeds)