2 lb. frozen hashbrowns
1 pt. sour cream
1/4 c. chopped onion or 1 tbsp. dry minced onion
1 can (undiluted) cream of mushroom or celery soup
Cheese, grated

Mix above ingredients and put in buttered casserole. Bake at 350 degrees for 1 1/2 hours. Cover last 1/2 hour. You may need to add a little milk if mixture is too dry. Reserve some of the cheese and sprinkle on top before baking.