- 1 tablespoon olive oil
- 1 pound mild Italian sausage, casings removed
- 1 onion, chopped
- 1 carrot, chopped
- 1 rib celery, chopped
- 1 clove garlic, minced
- 1/2 teaspoon dried thyme
- 1 bay leaf
- 4 cups drained and rinsed canned white beans, preferably cannellini
- 10 cups water
- 1 cup canned diced tomatoes with their juice
- 2 teaspoons salt
- 1 teaspoon fresh-ground black pepper
- 2/3 pound spinach, stems removed and leaves washed well
- Grated Parmesan, for serving
- In a large pot, heat the oil over moderately high heat. Add the sausage and cook, stirring frequently, until browned, about 5 minutes. Remove the sausage with a slotted spoon.
- Reduce the heat to moderate. Add the onion, carrot, celery, garlic, thyme, and bay leaf to the pot and cook, stirring occasionally, until the vegetables soften, about 10 minutes.
- Meanwhile, combine 2 cups of the beans and 2 cups of the water in a blender and puree until smooth.
- Add the tomatoes, the bean puree, the remaining 8 cups water, the salt, and the pepper to the pot. Bring to a boil, skimming any foam that rises to the surface. Stir in the sausage, the remaining 2 cups beans, and the spinach. Simmer until the spinach wilts, about 3 minutes. Serve the soup topped with grated Parmesan, and pass more Parmesan at the table.