Hash Brown Casserole

The other day I got to thinking about recipes that I haven't had in years-- and hash brown casserole was one of the first that came to mind.  It might be an oldie, but it's a goodie.  I can't believe I went so long without having this, oh so good, creamy, cheesy, comforting casserole.

Hash Brown Casserole

1/4 cup butter, plus more for greasing the dish
1 onion, chopped
1- 16 oz container sour cream
1- 10.5 oz can cream of mushroom soup
1- 8 oz package shredded cheddar cheese
1- 30 oz package frozen hash browns, thawed
1 tsp salt
1/2 tsp black pepper
1/2 tsp garlic powder
2 cups crushed potato chips

Preheat the oven to 350 degrees.  In a skillet melt the butter over medium heat.  Add the onion and saute until soft; set aside.  In a large bowl combine the sauteed onion, sour cream, cream of mushroom soup, cheese, hash browns, salt, pepper, and garlic powder; mix well.  Pour the mixture into a well greased 9x13-inch dish.  Top with the crushed potato chips and bake for 45 minutes, until hot and bubbly.