In 10-inch cast-iron or ovenproof skillet, cook sausage over medium-high heat 5 to 7 minutes or until no longer pink. Meanwhile, in medium bowl, stir together gravy mix and milk with whisk until well blended. Add gravy mixture to cooked sausage. Cook 2 to 4 minutes, stirring constantly, until gravy thickens. Stir in hard-cooked eggs; mix well.