In a large Dutch oven or soup pot over medium heat, cook the sausage, onion, and garlic for 5 minutes, or until the onion has softened and the sausage is browned. Remove any excess fat drippings.
Add the chicken broth, cream, cannellini beans, and sweet potatoes. Cover the pot and bring the soup to a boil. Then reduce the heat to low and simmer for 15 minutes.
Stir in the kale and cook for 5 more minutes, still covered. Serve each bowl of soup with a slice of rustic bread.