In a large stockpot cook the ground beef, sausage, pepperoni, green bell pepper, red bell pepper, garlic, onion, carrots and celery. Cook until beef is no longer pink. Drain into a large colander to drain grease.
To the large saucepot, add the mushrooms, tomato sauce, tomatoes, tomato paste, bouillon cubes, bay leaves, thyme, oregano, basil, crushed red pepper, black pepper, sugar, and beef broth and stir well. Pour the meat mixture into the pot. Bring to a boil, reduce heat and cover. Simmer for 2 hours.