Heat oven to 350 degrees. Mix meat, 1 1/3 cup instant potatoes (dry), the egg, seasonings, onion, catsup and milk. Spread in ungreased pie pan, 9x1 1/2 inches. Bake uncovered 35 minutes until ground beef is done. Drain fat if you want from pie pan.
Prepare remaining instant patotoes as directed on package for 4 servings. Top baked meat loaf with mashed potatoes, sprinkle with cheese. Bake 3 to 4 minutes longer or until cheese melts.