Zereh, the definition of casserole is cooking foods you like together in one dish. It doesn't have to involve "cream of" soups, sausage or hamburger.
My grandmother made wonderful scalloped potatoes. She started with her own homemade cream sauce (which is no big deal to make). Butter a casserole dish, and single layer thinly sliced potatoes on the bottom. Top with S&P, finely diced onions, and a scoop of cream sauce. Repeat layers until dish is within 3/4" from the top. Place on foil covered baking sheet to catch drips, cover with lid, and bake in 350 degree oven about 45 minutes, or until potatoes are tender. Remove lid, top with cheese of your choice, turn heat up to 400, and let the dish brown until cheese is melted and bubbly.
Excellent additions to this dish are: small pieces of ham; cooked and crumbled bacon, fresh chopped parsley, pimentoes, broccoli florets, asparagus tips, frozen peas, chopped green onion tops...a good combination is chopped cooked chicken, peas, carrots, and mushrooms.
Kimbaby, I have a whole different Tator Tot Casserole, but I think you'll like it:
Tator Tot Casserole
2 eggs
1 cup milk
2 cups cheddar cheese, grated
1 cup ham, choped
1 lb. tator tots, thawed
1 tsp salt
1/2 tsp white pepper
Topping:
2 cups cheddar cheese, shredded
1/2 cup cooked crumbled bacon
Mix first 7 ingredients together. Put in buttered baking dish. Sprinkle with topping. Bake uncovered at 350 degrees for 45 minutes.
I serve it with catsup on the side, forgive me for being so plebian.