Slow Cooker Ribollita

Ingredients

• 1 pound dried cannellini beans
• 2 tablespoons extra-virgin olive oil
• 1 large sweet onion, small-diced
• Kosher salt
• 2 large carrots, small-diced
• 3 celery stalks, small-diced
• 1/2 large butternut squash, peeled and small-diced (2 cups)
• 1 head garlic, cloves separated, peeled, and thinly sliced
• 1 (28-ounce) can San Marzano tomatoes, drained
• Bouquet garni: 2 bay leaves plus a couple sprigs each of fresh sage, oregano, flat-leaf parsley, and thyme, tied together with twine
• 1 tablespoon crushed red pepper flakes
• 1 pound cavolo nero (a.k.a. dinosaur kale or Tuscan kale), leaves torn into small pieces, stems finely minced
• 3 cups torn country bread, toasted
• 1 1/2 cups finely grated Parmigiano-Reggiano cheese
• 6-quart (or larger) slow cooker

Directions

1. Place the beans in a large bowl and add cold water to cover by 3 inches. Cover the bowl and soak the beans in the refrigerator overnight.
2. The next day, pour the beans and their soaking liquid into a slow cooker. Add enough fresh water to cover the beans by 2 inches, cover with the lid, and cook on the high setting for 4 hours.
3. Place a very large sauté pan over medium heat. Add the olive oil, and when the oil shimmers, add the onion. Season with salt and cook for 5 minutes, stirring every minute or so, until softened. Add the carrots, celery, butternut squash, and garlic, and cook for 5 more minutes, until starting to soften. Transfer the vegetables to the slow cooker. Add the tomatoes, crushing each one in your hand as you add it. Add the bouquet garni, 1 tablespoon salt, and 1/2 tablespoon of the red pepper flakes. Cook on the low setting for 3 hours.
4. Uncover the slow cooker, remove the bouquet garni, and add the kale, bread, 1 cup of the Parmigiano-Reggiano, and the remaining 1/2 tablespoon red pepper flakes. Stir the soup well, season with more salt to taste, and serve with the remaining Parmigiano-Reggiano sprinkled on top.