I am not above using canned soups in my recipes! This casserole is quick, easy and yummy!
2 lbs frozen, shredded hash browns
1 can cream of mushroom soup
1/2 stick melted margarine
1/2 cup sour cream
1 cup grated cheddar cheese
1/2 cup chopped onion
Mix all ingredients together in a bowl. Spread into a 9x13 inch pan. Bake at 350 degrees for one hour.