Cavolo nero is also known as Tuscan kale. American food authority Harold McGee says it belongs to that branch of the cabbage or brassica family that is the original wild cabbage, and native to the Mediterranean coast. The climate there — which is sunny and salty but not necessarily warm — results in these vegetables having juicy, waxy leaves. McGee also notes that such plants were domesticated about 2500 years ago, so it has been around for a long time.
The whole cabbage family became a European staple owing to its tolerance of cold climates. Cavolo nero has stippled, plume-shaped leaves with thick stalks. It is a dark blue-green colour and gets its name (cavolo nero or black cabbage) because when it is cooked in the traditional Tuscan way, it turns almost black. Long cooking produces a shiny appearance with an almost melted silky texture and a pleasant, slightly bitter flavour.
Cooking
It should not be undercooked and all the references to it in my Italian books say to cook it by boiling or steaming for a minimum of 20 minutes. But Italian chef Giorgio Locatelli in his book, Made in Italy says "The cabbage doesn't look black at all when it is raw — it is a dark green colour, but once it has been cooked properly (for around 40 minutes) it turns completely black — don't listen to anyone who suggests just blanching cavolo nero briefly, because such short cooking doesn't bring out the flavour or soften the bitterness."
I trust the wisdom of traditional cuisines to deliver good food because all such cuisines have knocked themselves out for centuries working out the best way to get the best results. Don’t follow the fad that has enveloped curly kale and cook it briefly. Lightly steamed or sauteed kale is like eating paper and kale crisps to me are simply a flavourless crisp texture — another example of Kiwis not really understanding an ingredient, or cooks merely using kale crisps as a new age culinary accessory.
As for using it raw in a smoothie, well I’d rather empty some lawn clippings into the blender and use them, much cheaper and I would think possibly more tasty. Using it raw in a salad would be a travesty. I have eaten cavolo nero in Tuscany well cooked and it is delicious. Get over any nutritional nonsense about only lightly cooking all vegetables — some need long cooking, others don’t, cavolo nero isn’t one of the latter. Would you lightly cook a potato? Like all vegetables — and this is all anyone needs to know — cavolo nero is good for you.
Buying
When buying cavolo nero, look for unwilted, unblemished leaves with no holes. It is often available in the mainstream supermarkets these days.
Try this
Before cooking it strip off the leaves from the thick bottom part of the stalks, which are discarded. It can be steamed or boiled gently until meltingly tender or slow fried with extra virgin olive oil, finely chopped onion, garlic and perhaps some chilli flakes — adding a little water or stock now and again and letting it evaporate as if making a risotto — until the cavolo nero is very tender.
In Tuscany it is used in the classic soup ribollita, (“ribollita” means twice-cooked because the soup is made the day before it is needed, then reheated in the oven next day) a soup which is not like minestrone (not brothy and no pasta) but more like a thick chunky puree of beans, bread and vegetables. The other Tuscan celebration of this vegetable is to use it on bruschetta, toasted (not baked) sourdough bread slices, well rubbed with garlic. The cooked cavolo nero is piled on top and the whole lot drizzled with extra virgin olive oil and seasoned simply with salt and pepper — Tuscan soul food.
As long as it is properly cooked, cavolo nero is a great side vegetable for pork, chicken or beef. Tender cavolo nero is good with white beans, garlic, extra virgin olive oil and a squeeze of lemon juice or a splash of white wine vinegar. I, untraditionally, like it with a good dusting of freshly grated parmesan. With a little grated smoked cheese it makes a delicious ravioli filling.
Buon appetito!