Kale is a very handy ingredient for seasonal eaters as it is one of the few green vegetables that is more abundant and flavourful during the coldest months of the year. It can be substituted for cabbage or spinach and makes a fine side dish when blanched and sautéed with garlic (a little soy and a sprinkling of chopped, roasted nuts is a lovely addition). It also makes an excellent ingredient in hearty, warming soups such as Kale and Chestnut Soup and the traditional Portuguese dish Caldo Verde.
Kale has been cultivated for over 2,000 years. In much of Europe it was the most widely eaten green vegetable until the Middle Ages when cabbages became more popular. Historically it has been particularly important in colder regions due to its resistance to frost. In nineteenth century Scotland kail was used as a generic term for 'dinner' and all kitchens featured a kail-pot for cooking.
A member of the same family as the cabbage - Brassica oleracea - most of the kale eaten in this country is curly leaved and belongs to the species acephala. Flat leaved kales are also grown but tend to be tougher and are now used mainly for animal feed.
Kale should have a fresh green color with moist, crisp, unwilted leaves. Young, small-leaved specimens are more tender; bigger leaves are well suited for use in soups.
Keep in a plastic bag in the fridge. Kale becomes increasingly bitter and strongly flavoured the longer it is kept and so is best eaten soon after buying.
Give kale a good wash in a sinkful of water to remove any dirt clinging to the inside of the leaves. If the stems are very small and tender they can be cooked with the leaves. Stems that are thicker, but still tender, can be cut off and cooked for a minute or two before the leaves are added. Any thick, tough stalks should be discarded.
Kale has a relatively low moisture content and therefore does not shrink as much as other greens and requires a longer cooking time. Except when very young, kale is not particularly pleasant when undercooked and should be served just soft rather than al dente. Steam, simmer or saute gently for several minutes until thoroughly tender. Some stock can be added for extra flavour.
Early in the twentieth century, Kailyard (kale field) was a disparaging term used to describe a school of Scottish writers, including Peter Pan author J. M. Barrie, whose writing featured sentimental nostalgia for rural Scottish life.