Melt butter in a pan or skillet, then add garlic and cook until fragrant
Add the flour and stir well until fully combined. Pour in the cream until the mixture thickens slightly. Make sure to stir continuously to prevent the mixture from burning
Add the blue cheese and mix until the crumbled pieces melt and incorporate into the sauce
Season with salt and pepper to taste, place on a serving container and serve. You can also pour it directly over the flank steak before serving