In an extra-large skillet cook sausage, onions, and garlic over medium-high heat until browned. Drain off fat. Let cool.
Divide cooked sausage mixture, Swiss chard, tomatoes, and Italian seasoning among three 1-gallon resealable plastic freezer bags. Squeeze air from bags, seal, label, and freeze up to 3 months.
In a 4-quart Dutch oven bring broth to boiling; add frozen ingredients, breaking apart as necessary. Return to boiling; reduce heat. Simmer, uncovered, 10 minutes, stirring occasionally. Add pasta. Cook 12 minutes more or until pasta is tender, stirring occasionally. If desired, serve with shredded Parmesan cheese.