Cook the beef, onion, and celery until the meat is browned. Drain off excess fat. Stir in the tomato sauce, water, oregano, and chili powder. Season the eggplant slices with salt & pepper. Arrange on top of meat sauce. Cover and simmer until the eggplant is tender, 15 to 20 minutes. Top with shredded process American cheese and sprinkle with paprika. Serve with Parmesan cheese. Makes 4 - 5 servings