Potatoe Sausage Casserole

I got this idea from a recipe in my MasterCook software. This version is with my modifications. Family loved it.

1 pound ground sausage
1 can cream of mushroom soup
3/4 c milk
salt and pepper
1 large diced onion
1 package frozen hashbrowns (the diced kind)
1/2 pound shredded mozzarella cheese (or whatever kind you have)

Brown sausage. When mostly done, add onions and cook until soft. Mix soup, milk, salt and pepper. Add sausage/onion mixture and 3/4 of cheese. Put in large casserole dish. Dot with butter. Bake covered pan at 350ºF for 30 to 45 minutes. Sprinkle with grated cheese and melt in oven.