Pour drippings from roasting pan into bowl, leaving brown particles in pan. Return 1/4 cup drippings to roasting pan. (Measure accurately because too little fat makes gravy lumpy.) Stir in flour. (Measure accurately so gravy is not greasy.)
Cook over medium heat, stirring constantly, until mixture is smooth and bubbly. Stir in liquid. Heat to boiling, stirring constantly. Boil and stir 1 minute. Stir in salt and pepper.
