Ribollita

Cold-weather cabbage soup adapted from Mario Batali.
Ingredients
1/4 cup extra virgin olive oil
1 Spanish onion, thinly sliced
1 leek, white and light green parts only, thinly sliced [be sure to cut it vertically first and to wash the layers under running water, or you might get sand in your soup]
2 carrots, cut into 1/4-inch dice
2 celery stalks, cut into 1/4-inch dice
2 to 3 garlic cloves, thinly sliced, plus 1 whole garlic clove
2 sprigs fresh thyme or rosemary or both
1 bay leaf
1 pound roughly chopped cavolo nero (black cabbage)
1/2 pound roughly chopped white cabbage
2 tablespoons tomato paste
1 can Cannellini beans, drained (but not rinsed)
4 to 6 cups water (or more, if necessary)
Italian peasant bread or sourdough, sliced thickly
Salt and pepper
Freshly grated Parmesan
Instructions
n a Dutch oven or large pot, heat the olive oil and add the onion, leek, carrot, celery, sliced garlic and herbs. Sprinkle gently with salt, stir and cook until the vegetables are soft but not at all brown. Add the black and white cabbage, sprinkle again with salt, and cook until they’ve softened and the flavors have blended, about 10 minutes. Taste and adjust for salt and pepper. Remove the rosemary, thyme and bay leaf. Add the tomato paste and stir until it’s well distributed throughout the vegetable mixture. Add the beans and enough water to make it look soupy (about 6 cups). (You could also add a Parmesan rind here, if you have one.) Sprinkle again with salt, stir all around and simmer for 30 minutes until the soup thickens slightly and tastes great (you may need to adjust with more salt and pepper). Meanwhile, place the bread under the broiler and toast, on both sides, until deep dark brown. Rub the toasted bread with a raw garlic clove and drizzle with olive oil. Ladle the soup into bowls and serve up with the toasted bread (Mario calls it “garlic bruschetta”) and Parmesan for grating on top