Seasonal food: kale

Brassica oleracea is the most intrepid member of the cabbage family, with a well-deserved reputation for being able to grow anywhere. Domesticated before 600BC, the original wild cabbage still grows around the shores of the Mediterranean and selective breeding in the intervening centuries has given rise to plants as varied as cabbage, brussels sprouts, kohlrabi, broccoli and cauliflower. Unlike firm-headed cabbages, kale is distinguished by having no heart, but the open form means the leaves accumulate more vitamins A and C, and more antioxidant carotenoids than varieties whose tightly furled inner leaves never see daylight. The English name comes from the same word in Scots and replaced the earlier 'cole'. Scottish kale is a curly-leaved variety in its own right. All varieties are best when young and curly kale is more tender than the flat leaved varieties. In a similar manner to the parsnip, kale is sweeter after frost. Varieties Black kale (cavalo nero) Flat leaved (Russian kale) Curly leaved (curly kale) How to buy / what to look for Curly kale - smaller, firm green leaves. Cavalo nero - firm leaves with white ends to the stalks. Nutrition A useful source of vitamins C, A and B6, and calcium. Harvested June - February Storage Best eaten as soon as possible after harvesting, but if needs must keep in a paper bag in the fridge for 3-4 days (the chill will help ward off bitterness). Basic cooking Trim away the thicker parts of the stalks, chop coarsely and steam or boil in salted water for a few minutes as you would with spinach or cabbage. If you're growing it yourself, tiny leaves can be tossed raw into salads. Goes with / good in Pork, pulses and beans, in soups, stews and stir fries. Recipes Nigel Slater's kale with oyster sauce and toasted sesame seeds Hugh Fearnley-Whittingstall's chestnut, kale and chorizo soup Nigel Slater's kale with chorizo and almonds Ross Dobson's sage pork chops with kale colcannon Hugh Fearnley-Whittingstall's chicken, spelt and kale soup