1. Gather all necessary ingredients and tools: butter, garlic, Parmesan cheese, heavy cream, milk, flour, salt, black pepper, parsley, red pepper flakes (optional), and any additional seasonings or variations you’d like to include.

2. Prepare a medium saucepan and place it over medium heat.

3. Add 4 tablespoons of unsalted butter to the pan and let it melt completely, ensuring it doesn’t brown.

4. Once melted, add 4 cloves of minced garlic to the saucepan and sauté for 1-2 minutes until fragrant, stirring constantly to avoid burning.

5. Slowly sprinkle 1 tablespoon of flour onto the butter and garlic mixture, whisking continuously to combine and remove any lumps, creating a roux.

6. Cook the roux for 1-2 minutes to eliminate the raw flour taste, being careful not to let it turn too dark.

7. Gradually pour 1 cup of heavy cream into the saucepan while whisking to ensure smoothness, followed by ½ cup of milk, continuing to whisk.

8. Let the sauce cook for about 3-4 minutes, stirring frequently until it starts to thicken.

9. Incorporate ½ cup of freshly grated Parmesan cheese into the mixture, stirring until fully melted and the sauce becomes smooth.

10. If the sauce is too thick, add a splash of milk to adjust its consistency.

11. Season the sauce with ½ teaspoon of salt and ¼ teaspoon of freshly ground black pepper. Add Italian seasoning, onion powder, or garlic powder if desired.

12. Lower the heat and let the sauce simmer for 2-3 minutes, stirring occasionally.

13. Taste the sauce and adjust the seasoning as needed, adding red pepper flakes for spice if desired.

14. Once the sauce has reached your desired consistency, remove it from the heat.

15. Optional: Garnish with 1 tablespoon of freshly chopped parsley for added freshness and visual appeal.

16. Serve the sauce hot as a dip, pizza base, pasta sauce, or accompaniment for your favorite dishes.