Start by melting butter in a saucepan over medium heat. Once melted, add minced garlic and sauté until fragrant. This step builds a flavorful base for the sauce.
Sprinkle in the flour and whisk continuously to combine with the butter. Cook for about a minute to remove the raw flour taste. This mixture will help thicken your sauce later.
Slowly pour in the half-and-half and chicken broth while whisking. This prevents lumps and ensures a smooth texture. Keep stirring as the mixture begins to thicken.
Stir in Italian seasoning, salt, and pepper. Gradually add freshly grated Parmesan cheese, allowing it to melt fully. The sauce should become creamy and rich at this stage.
If using spinach or sun-dried tomatoes, add them now. Let the sauce simmer gently until it reaches your desired thickness. Stir occasionally to keep it smooth.
Add cooked ravioli directly into the sauce or pour the sauce over plated ravioli. Toss gently to coat each piece evenly. Serve immediately for the best flavor.