Whip up a big pot of this winter soup on a Sunday and enjoy it all week long.
Place bacon in a small stockpot, and place over medium heat; cook, stirring occasionally, until crisp, about 6 minutes. Remove bacon, and set aside. Add onions and garlic to hot bacon fat, and cook until onions are translucent, about 8 minutes. Add carrots, celery, and pepper, and cook for 5 minutes.
Add northern, rattlesnake, and pinto beans, chicken stock, 5 1/2 cups water, and rosemary, and bring to a boil. Reduce heat to medium low, and simmer 30 minutes. Add cabbage, and simmer until beans are tender, 25 to 30 minutes. Ten minutes before soup is done, stir in salt and reserved bacon.
Stir in bread, and simmer until bread has totally softened and just begins to break down, about 10 minutes. Adjust seasoning to taste with salt and pepper if necessary. Serve ribollita drizzled with a good-quality extra-virgin olive oil and sprinkled with Parmesan, if desired.
Any combination of beans can be used. However, it's best to select an assortment in the same size range to ensure even cooking. If you choose large beans, adjust the cooking time accordingly.