Black kale / Cavolo nero / Nero do toscana
 
The exceptional nutritional properties of kale were recognised in the "Dig for Victory" campaign of World War ll. Easy to grow, well on into winter, the hardiest of our vegetables and actually tasting better after a frost, kale is a source of nutrients at levels unknown in other foods. With more folates than broccoli, four times as much magnesium and calcium as Brussels sprouts, seven times more carotene than cabbage, 17 times the vitamin C content of carrots, and 75 times the lutein content of carrots, kale has rightly been called a "superfood". Its unusually high levels of both lutein and zeaxanthin help keep eyes healthy and in particular reduce the risk of cataract and age-related macular degeneration.
 
Kale is a non-hearting form of cabbage, ancestors of which were known in ancient Greece and which till the end of the middle ages was perhaps the most common green vegetable in Europe. It is an ingredient in traditional dishes from all over Europe, from Irish colcannon to Tuscan ribollita. In parts of north-west Germany kale is at the centre of much community culture, with an annual kale festival, a kale king or queen, and Grunkohlfahrt (kale tours) from October to February, with country inns providing boiled kale, Mettwurst and schnapps.
 
Black Kale, or Cavolo Nero, (and its cousin Nero di Toscana), originates from Tuscany, although it grows well in the UK. It has long loose leaves of deep greenish black, with a coarse central stalk. Very versatile, it can be used in soups, salads and works particularly well in slow-cooked dishes like the Florentine ribollita toscana.