Spray a 9 x 13 x 2 pan with no stick cooking spray.
Spread the onions evenly in the bottom of the panLayer the potatoes evenly on top of the onions, sprinkle with salt, pepper and paprika.Evenly crumble the ground beef over the potatoes and sprinkle with rice. Add little more salt, pepper and paprika.Layer the celery evenly.Add diced tomatoes in an even layer. Add a little more paprika.In a small bowl, mix the tomato soup with ½ soup can of water. Pour over the casserole.
Bake at 350℉ for 1½ - 2 hrs. When potatoes and celery are cooked, top the casserole with grated cheddar cheese and return to oven until cheese is melted.Let stand for 5 minutes, cut into squares and serve.
Notes
I use salt and pepper very sparingly. Lightly sprinkle paprika between layers.