Preheat oven to 350°F. Mix Gravy Mix, ground beef, minced onion and pepper in large bowl. Shape into a loaf, 2 inches high, in shallow baking pan.
Stir chives into prepared mashed potatoes. Spread over meat loaf.
Bake 55 minutes or until cooked through. Sprinkle with cheese. Bake 2 minutes longer or until cheese melts.