Potato Cheese Casserole

2 pound bag of frozen hash brown potatoes
2 tablespoons minced onion
1 can of cream of mushroom soup
1 pint sour cream
2 cups shredded cheese
1 stick of butter, melted
salt and pepper to taste

Mix all ingredients in a bowl. Pour into a 9x12 baking dish. Bake at 350° for 1 hour or until tender and golden brown.

Note: substitute cream of chicken soup for the mushroom soup for a different flavor