PREHEAT oven to 400°F. Cut a 1/2-inch-thick slice off top of round bread loaf. Remove interior of loaf, leaving a 1/4-inch-thick shell. Spread all cut sides of loaf evenly with 1/4 cup Miracle Whip Mustard Mania Dressing.
FILL bread shell with layers of 125 g deli sliced ham, 1 each sliced tomato and onion and 1 cup Kraft Mozza-Cheddar Shredded Cheese. Wrap in foil.
BAKE 30 minutes or until cheese is melted. Let stand 10 minutes before unwrapping and cutting into 4 wedges to serve.