Ribollita in a Slow Cooker

Ribollita in a Slow Cooker
1 pound dried cannellini beans, rinsed and drained
1 head garlic, halved horizontally & discard loose paper skin
1-2 sprigs fresh sage
4 cups reduced-sodium chicken broth, vegetable broth, or water
1 28 oz can whole peeled tomatoes in puree, undrained, cut up
6 tablespoons olive oil
Salt
Ground black pepper
2/3 cup chopped pancetta (optional)
1 cup chopped onion (1 large)
1 cup chopped carrots (2 medium)
1 cup chopped celery (2 stalks)
2 tsp snipped fresh thyme or 1 tsp dried thyme, crushed
2 cloves garlic, minced
4 cups chopped kale or Swiss chard
1 cup snipped fresh parsley
8 slices Italian bread
1 clove garlic
½ cup freshly grated Parmesan cheese
Olive oil (optional)

Place beans in a large Dutch Oven; add enough water to cover. Bring to boiling; boil gently for 10 minutes. Cover and let stand for 1 hour.
Drain & rinse the beans. Set aside. Cut an 8-inch square from a double thickness of 100% cotton cheesecloth. Place the halved garlic head & sage in center of cheesecloth square. Bring up the corners; tie closed with 100% cotton kitchen string. In a 5-to-6-quart slow cooker combine beans, garlic-sage packet, broth, tomatoes, 2 tablespoons of the olive oil, 1/2 teaspoon salt, and 1/4 teaspoon pepper. Cover & simmer on high-heat setting for 5 to 6 hours (10 to 12 hours at low heat) or until beans are tender but not mushy.
Discard garlic-sage packet. Use a potato masher to slightly mash some of the beans (this will thicken the soup a little).
In a large skillet heat 2 tablespoons of the olive oil over medium-high heat. Add pancetta, if using; cook & stir for 3 to 5 minutes or until browned. Add onion, carrots, celery, & 1/2 teaspoon salt. Cook & stir about 5 minutes or until onion is tender. Stir in thyme & minced garlic; cook about 30 seconds more.
If using low-heat setting, turn cooker to high-heat setting. Stir vegetable mixture into mixture in slow cooker. Cover & cook about 1 hour more or until vegetables are soft & soup has thickened slightly. Stir in kale & parsley. (This soup is best when you allow the flavors to meld, make this the day before cover & chill for up to 24 hours.
To serve, preheat oven to 350 degrees F. Arrange bread slices on baking sheet; brush both sides of each slice lightly with the remaining 2 tablespoons oil. Bake about 10 minutes or until golden brown, turning once halfway through baking time. Cool bread slightly; lightly rub the whole garlic clove over one side of each piece of the hot toast. Reheat soup & place one toast in each bowl. Ladle hot soup over toast. Sprinkle individual servings with Parmesan cheese. If desired, drizzle with additional olive oil.