Meanwhile, in a large skillet, cook beef over medium heat for 6-8 minutes or until no longer pink, breaking into crumbles; drain. Stir in gravy mix. Add vegetables and water; bring to boil. Reduce heat; simmer until heated through, stirring occasionally. Transfer to a 9-in. square baking pan.
Spread potatoes over top; sprinkle with pepper. Broil 4-6 in. from the heat for 10-15 minutes or until golden brown.