Ribollita

Ingredients

• 3/4 cup dried cannellini beans, soaked overnight and drained
• 4 tablespoons extra-virgin olive oil
• 1 Spanish onion, thinly sliced
• 1 leek, white and light green parts only, thinly sliced
• 1 carrot, cut into 1/4-inch dice
• 1 celery stalk, cut into 1/4-inch dice
• 1 garlic clove, thinly sliced, plus 1 whole garlic clove
• 2 sprigs fresh thyme
• 1 bay leaf
• 1 pound chopped cavolo nero (black cabbage), roughly chopped
• 1/2 pound chopped white cabbage, roughly chopped
• 2 scant tablespoons tomato paste
• 3 cups water
• 4 (1/2-inch) slices Italian peasant bread
• Salt and freshly ground black pepper
• Freshly grated Parmigiano-Reggiano