Meanwhile, in a 4-quart Dutch oven cook onion and garlic in hot oil until tender. Carefully add chicken broth; bring to boiling. Stir in pasta; reduce heat and boil gently for 5 minutes. Stir in asparagus and snow peas. Return soup to boiling; cook 3 minutes more. Stir in spinach and pepper; cook 1 minute more. Remove soup from heat. Ladle soup into bowls. If desired, swirl some pesto into each bowl of soup. Sprinkle Parmesan cheese on top of each serving. Makes 8 servings.