In a medium saucepan, melt 2 tablespoons of unsalted butter over medium heat. Add 4 cloves of minced garlic and sauté for about 1 minute, stirring frequently until fragrant but not browned.

Slowly pour in 1 cup of heavy cream while stirring gently to combine. Allow the mixture to come to a gentle simmer and cook for 2-3 minutes until slightly thickened.

Reduce heat to low and gradually stir in ½ cup of freshly grated Parmesan cheese until melted and smooth.

Add ½ teaspoon of salt, ¼ teaspoon of black pepper, ½ teaspoon of Worcestershire sauce, and 1 teaspoon of Dijon mustard (if using). Let it simmer for another 2-3 minutes, stirring occasionally.

Once the sauce has reached your desired consistency, remove from heat. Transfer to a serving dish or drizzle over cooked steak and garnish with chopped parsley.