In a large Dutch oven, cook the sausage, onions, and garlic over medium-high heat until the sausage is browned and crumbly, about 6 minutes. Drain, if necessary. Stir in the broth, Swiss chard, and beans. Add salt and pepper, to taste. Bring to a boil; cover, reduce heat, and simmer until Swiss chard is tender, about 20 minutes. Serve immediately with mini cornbread muffins, if desired.