In a large saucepan, prepare macaroni and cheese according to instructions on package. Preheat oven to 350 degrees F
Stir in the cubed cheese, frankfurters, peas, onion, condensed tomato soup and condensed celery soup. Season with garlic powder, salt, and pepper. Spread into a 9x13 inch baking dish, and cover loosely with aluminum foil.
Bake in preheated over for 40 to 45 minutes.