In a large skillet over medium heat, cook sausage and onion until the sausage is no longer pink. Drain, reserving 2 tablespoons drippings in skillet. Stir flour into sausage and drippings until blended. Cook and stir until light golden brown. Gradually stir in milk and seasonings. Bring to a boil; cook and stir for 2 minutes or until thickened. Serve over biscuits. Yield: 6 servings (about 4 cups).