What is Cavolo nero?

Cavolo nero — An Italian cabbage with dark green leaves that have a good, strong flavour. It can be used in all cabbage recipes but it's particularly good in soups - such as the classic Tuscan soup, ribolitta, which is traditionally left to sit for a day before serving to allow the soup to thicken and the flavours to develop. Cavolo nero is delicious cooked simply, just fried in olive oil with garlic and…