In a Dutch oven or soup pot heat the olive oil. Add chopped onions and cook until onion is soft and translucent.
Add diced tomatoes, tomato soup, milk, basil and chicken broth to pot, stir and simmer for 20 minutes.
Add half and half and tortellini to soup pot, stir and cook for another 15 minutes or until tortellini is cooked.
Serve and garnish each individual soup bowl with extra basil and Parmesan cheese.