In a large stockpot, heat oil. Add garlic and cook about 1 minute.Add chicken and cook for and additional 1-2 minutes. (or until chicken is cooked if you are using uncooked chicken)Add broth and tomatoes. Bring to a boil.Add tortellini and cook 3-4 minutes or until the tortellini begins to fluff up and soften.Stir in spinach and pepper. Cook until spinach is wilted.Sprinkle with 1 tablespoon shaved Parmesan cheese or 1 teaspoon grated Parmesan cheese, if desired.