If the tomato is Italy's summer vegetable, especially in the south, Cabbage is probably the winter vegetable: The flowering varieties, especially broccoli raab and cauliflower in the south, and head cabbages in the north. And where does that leave the center?
Well, there's Cavolo Nero, Brassica oleracea acephala or black leaf kale, which Italians generally associate with Tuscany: It's a leafy cabbage that doesn't form heads, but rather resembles palm fronds, with deep greenish black leaves that can be up to a yard (a meter) long, have pronounced ribs, and whose surfaces have a distinctive bubbly appearance.
Cavolo Nero, or Kale: It's Good For You!
Indeed, very good; a cup contains considerably more than 50% of the minimum recommended daily allowances of vitamins K, A and C, with lesser but still significant amounts of manganese, copper, fiber, calcium, iron, the B vitamins, vitamin E, and many other elements. It is also rich in antioxidants, and is thought to help prevent a variety of conditions, ranging from stomach, colon and bladder cancer though ulcerative colitis. Finally, it's both filling and low in calories, 19-26 per 100 grams (or quarter pound), which leads Italian doctors to recommend it to those who want to loose weight.
Cavolo Nero, or Kale: Finding It
In Italy kale is generally just labeled Cavolo Nero, though you can also find it identified as cavolo toscano, cavolo palmizio, or cavolo a penna, while agricultural treatises mention specific cultivars, for example cavolo nero fiorentino, cavolo riccio nero di toscana, and cavolo riccio nero di Lucca.
In the English-speaking world some call it Cavolo Nero, while others call it dinosaur kale or laciniato kale or cabbage (laciniato is a botanical term that means uneven, like a fringe, and refers to the leaves). You may have better luck finding it in an organic produce market than in a larger less specialized market. If you simply cannot find it, seeds are readily available on the Internet, and it is easy to grow.
Cavolo Nero, or Kale: Purchasing and Storing It
Though black leaf kale appears in the markets in November and continues through spring, it's best when the leaves have felt the sting of frost, which brings out a pleasing sweetness. In purchasing it, you'll want leaves that aren't too long -- beyond 18 inches (50 cm) the leaves begin to toughen, and taste sharper -- firm, and fairly evenly colored and shaped: Darker areas are fine, but if you see paler green, brown, or yellow, or holes, think about buying something else.
Once you get your kale home, you can store it for a day or two in the crisper section of the refrigerator, with the stem end wrapped in a moist paper or cloth towel to keep it from drying out. Don't wash it until you plant to cook it, because it may go limp. Come cooking time, wash it well. The ribs are edible, though they take much longer to cook than the leaves, especially if they're thick, and you may therefore want to remove them: fold the leaves lengthwise with one hand, grasp the exposed ribs with the other, and pull in opposite directions. Most recipes then have you cut the ribless leaves into strips.
Last thing: Don kindly writes,
"Cavolo nero also freezes well. Strip the ribs out of the leaves. Cut the green parts crossways into strips about half an inch wide, and blanch the cavolo nero in salted boiling water. Drain and refresh in cold water; then squeeze the water out and freeze the leaves in quart freezer bags, flattening them out to about 3/4 of an inch thick and laying them on a metal tray for quick freezing. The frozen cavolo nero can be easily used by slicing open the bag. This works perfectly in soups or reheated in broth and spooned over toasted bread."
Cavolo Nero, or Kale: Serving it as a Side Dish
To serve 4 figure about 2 pounds (1 k) kale; wash the leaves well and strip away and discard the ribs, then coarsely chop the leaves and put them in a pot. Heat, using the water that remains on the leaves to provide moisture, and cook them over a moderate flame for 20-25 minutes, stirring them about occasionally. You could also steam them, which will preserve more of the nutrients. Drain the leaves well, and in the meantime heat a clove or two of garlic and 3-4 tablespoons of olive oil in a broad skillet. Toss the kale in the oil, stirring it about for a minute or two, season to taste with salt and pepper, and it's ready. If you want a slightly richer dish, rather than olive oil take a 1/4-inch (.5 cm) slice of pancetta, dice it, and heat it with the garlic for a couple of minutes before adding the kale.
Not looking for a side dish? Some Recipes