Heat large skillet over medium heat. Add sausage; cook 10 to 12 minutes until crumbled and browned, stirring occasionally. Remove sausage. Stir flour into 4 tablespoons drippings remaining in skillet and cook about 2 minutes, stirring constantly. Add milk and cook about 5 minutes until thickened and bubbly. Add additional milk if gravy seems too thick. Add sausage to gravy. Season with salt and pepper. Serve immediately over hot biscuits or potatoes.