Crockpot Ribollita

3-4 carrots, roughly chopped3 celery stalks, roughly chopped3 c. green cabbage, sliced4 oz. pancetta, diced1 c. dried cannellini beans, rinsed¼ c. tomato paste½ c. grated parmesan cheeseKosher salt, black pepper5 thick slices of crusty bread¼ c. chopped fresh parsley3 T.…