A member of the Mustard family, which includes Brassicas, Kale originated in the Eastern Mediterranean. Varieties come in serrated, crinkly, curly, flat or deeply cut and feathery, and in colours from pink-edged silvery green through pale to dark, almost black, green and deepest purple. Blistered-leaved Cavolo Nero/Nero de Toscana is considered a Kale despite its ‘Black Cabbage’ translation.
Sharing bitter-sweet and peppery flavours with their relatives Cabbages and Brussels Sprouts, like them, Kale develop their best flavour and colour after a period of cold weather, particularly after frost. This activates the natural sugars in the plants. A cut-and-come-again plant, they are at their best during the January to March ‘hunger-gap’ when northern hemisphere greens are few and far between. Kale is rich in vitamins A, C and K, folic acid and manganese.
Kale can be eaten raw in a salad, after discarding any tough stalks. Their leaves can be torn and tossed in olive oil and a little salt before baking in a medium oven for 15 minutes to produce kale crisps. Tender young leaves can be sautéed briefly in a little olive oil with garlic, and, optionally, chilli. Later, larger leaves need to be chopped up and sautéed after first blanching in salted boiling water. Romans call this treatment ripassate. You can add raw Kale leaves to a soup. The leaves are particularly good with potatoes and add an earthy depth to mixed vegetable soups. Kale pairs beautifully with salty fried bacon or anchovies melted in hot butter. The leaves also have an affinity with eggs – add cooked kale to a frittata or tortilla or top with a poached egg and, maybe, a little grated gruyère for a quick lunch.