Saute onions, celery and garlic briefly in olive oil in large pot for about 2 minutes. Add hamburger and mushrooms and cook until no longer pink. Add soup, chili, chopped tomatoes, tomato sauce, bay leaf and oregano and salt and pepper and bring to boil. Reduce heat to simmer, cover and cook for about 1 hour, stirring occasionally.
Cook pasta and add to sauce, mix thoroughly and add grated cheese on top. Place lid on pot and let simmer until cheese melts.