In a large pot with lid, cook sausage, ground sirloin, onion, mushrooms, and garlic in olive oil over medium heat until well browned.
Stir in crushed tomatoes, tomato paste, tomato sauce, and balsamic vinegar.
Season with sugar, basil, oregano, thyme, bay leaves, fennel seeds, Italian seasoning, salt, pepper, and parsley.
Simmer on low, covered, for at least 1½ - 2 hours, stirring occasionally.