The traditional Italian green for this soup is Tuscan kale, known as “cavolo nero” (black cabbage). It is a somewhat tangy green that develops a subtle sweetness during cooking. Many American grocery stores, and seed catalogues, market it as “Lacinato” or “dinosaur kale”. Regular kale may be substituted if your greengrocer has not yet caught up with the Tuscan variety.
2 cups dry cannellini (white kidney) or other medium-size white beans, like Great Northerns
2 medium onions
6 tablespoons extra-virgin olive oil
2 bay leaves
6 fresh sage leaves
4 ounces pancetta
6 peeled garlic cloves
1 large red or yellow onion (optional, you can use the two from the beans instead), finely chopped
4 large garlic cloves (optional, you can use the 6 from the beans instead), finely chopped
1 large celery stalk (optional, you can use the 2 from the beans instead), finely chopped
1 medium carrot, finely chopped
Salt and freshly ground black pepper
1 pound "cavolo nero" (dinosaur kale or Lacinato) or regular kale, stems removed, leaves washed and shredded
1/2 pound fresh, ripe tomatoes (about 1 cup chopped), or 1 cup drained, chopped canned plum tomatoes, or 1 cup tomato sauce
6 cups unsalted vegetable or meat broth (optional, you can use the liquid the beans cooked in, though you may want to add some meat broth or bouillon for extra flavor)
- Cover the beans with cold water by 2 inches and soak for four hours or more.
Put the beans in a pot and cover with water by 2 inches. Bring to a boil, boil 2 minutes, then cover and turn off the heat. Let the beans sit for 1 hour.
Fish the vegetables out of the pot and use a colander to separate the beans and the cooking liquid (if you are using broth for the soup, you can discard the bean cooking liquid).
Cook the soffritto: Measure the 3 tablespoons of oil into the pot and set it over medium-low heat. Stir the pancetta, onion, garlic, celery, and carrot into the warming oil, season with salt and pepper, and cook slowly and gently until the vegetables are tender, aromatic, and translucent, 15 to 10 minutes.
Add the vegetables:Scatter the kale over the soffritto, season with salt and pepper, stir it around to distribute the soffritto as evenly as possible, and cook over a moderate heat until the greens are wilted, about 7 minutes. Stir in the tomatoes, season, and cook 7 more minutes.
Cook the soup: Pour in the broth, and bring to a boil. Then reduce the heat, cover the pan, and simmer for 30 minutes. Add the beans to the soup, and cook, covered, for 20 minutes.