Ingredient:

• 1 package (16 ounces) spaghetti
• 1 package (13 to 14 ounces) smoked turkey sausage, thinly sliced
• 3 cups grape tomatoes, halved
• 2 cups fresh basil leaves, loosely packed
• 1 large onion, thinly sliced
• 4 garlic cloves, thinly sliced
• 4-1/2 cups water
• 1 cup grated Parmesan cheese
• 3/4 teaspoon salt
• 1/2 teaspoon pepper
• 3/4 teaspoon crushed red pepper flakes, optional