Chicken Tortellini Soup with Parmesan

1/4 C. olive oil
8oz. assorted mushrooms, sliced
2 large garlic cloves, minced
1 32oz. carton low sodium chicken broth
1 14.5oz can diced tomatoes with basil, garlic and oregano
2 9oz. packages refrigerated chicken tortellini
1/3 C. julienned fresh basil
1/4 tsp. pepper
1/4 C. grated Parmesan

Heat oil in a large pot over medium heat until hot.  Cook mushrooms and garlic 3 to 4 minutes or until mushrooms are softened.  Stir in broth and tomatoes; bring to a boil.  Add tortellini; simmer 9 to 10 minutes or until tortellini are tender, stirring occasionally.  Stir in basil and pepper wimmer 1 minute.  Serve, sprinkled with cheese.