Melt butter in a large skillet over medium heat. Whisk in the flour and cook until lightly browned, about 1 minute.
Gradually whisk in the cream, milk, Parmesan, and cream cheese until slightly thickened, about 2 minutes. If the mixture is too thick, add more heavy cream as needed.
Season with salt and pepper to taste.
Serve over steaks or steamed veggies.
Video
Notes
Store leftover sauce in an airtight container in the refrigerator for up to 4 days.When you are ready to use the sauce, warm it a saucepan over low heat. The sauce will be quite thick when it’s cold but should loosen as it warms. Add a little milk or heavy cream to thin it out if needed.Makes about 1 1/2 cups.