In a large pot or Dutch oven, heat 1 tablespoon of olive oil over medium high heat. Cook one pound ground Italian sausage and 1 cup diced onion over medium heat until browned.
Add in 4 cloves minced garlic and cook for about 60 seconds, until tender and fragrant.
Drain excess grease if necessary.
Pour in 4 cups chicken broth and 14.5 ounces diced tomatoes. Season with ½ teaspoon each of salt, pepper, and red pepper flake, and 1 teaspoon of Italian Seasoning.
Add 1.5 cups pasta and cook for about 8-10 minutes, or until pasta is al dente.
Stir in 1 cup heavy cream, and ½ cup finely grated Parmesan cheese. Simmer for 2-3 minutes until cream and cheese are well combined.
Adjust to taste with additional salt and pepper if needed. Garnish with fresh basil and serve hot.