Cheesy hash browns

2 pounds shredded hash browns
1/2 cup onion, chopped
1 pint sour cream
1 stick of butter, softened
2 cups shredded cheddar
1 can cream of chicken soup
Salt and pepper, to taste

Mix all the ingredients together. Stir in hash browns. Hash browns should be thawed overnight in fridge. Bake at 350 degrees for 45 minutes. Can be made ahead of time and refrigerated.