Garlicky Tortellini Soup With Sausage, Tomatoes, and Spinach

Ingredients (13)

• + 1 pound mild sausage, removed from casings add to pantry
• + 1 medium onion, finely chopped add to pantry
• + 6 cloves garlic, finely chopped add to pantry
• + 1 (32 ounce) carton chicken broth add to pantry
• + 1 (14 ounce) can chicken broth add to pantry
• + 1 pound frozen cheese tortellini add to pantry
• ✓ 1 (14 ounce) can diced tomatoes
• + 1 (10 ounce) package fresh spinach, coarsely chopped add to pantry
• + 10 leaves fresh basil, chopped add to pantry
• + ½ teaspoon red pepper flakes, or to taste add to pantry
• ✓ 1 pinch salt and ground black pepper to taste
• ✓ 1 pinch salt and ground black pepper to taste
• + ½ cup grated Parmesan cheese, or as needed add to pantry