I am sure everyone has their own version of this casserole but here is one I found on the food network. This recipe calls for crushed chips on top although I did not have these on hand so I used cornflakes instead. I was informed afterwards that the chips are the "key" to the deliciousness by a friend of mine. I will be sure to use them next time.
1/4 cup butter, plus more for dish
1 onion, chopped
1 (16-ounce) container sour cream
1 (10 1/2-ounce) can cream of celery soup
1 (8-ounce) package shredded Cheddar and Monterey Jack cheese blend (I just used cheddar)
1/2 teaspoon garlic powder
1 (30-ounce) package frozen shredded hash brown potatoes, thawed\ (I used the larger size hashbrowns)
1 teaspoon salt
1/2 teaspoon ground black pepper
2 cups crushed potato chips
Preheat oven to 350 degrees F. Lightly butter a casserole dish.
In a small skillet, melt 1/4 cup of butter over medium heat. Add onion, and cook 3 to 4 minutes, or until soft. Pour mixture into a large bowl. Add the sour cream, cream of celery soup, cheese, garlic powder, hash browns, and salt and pepper. Combine until well blended.
Pour mixture into prepared baking dish. Top evenly with crushed potato chips and bake for 45 minutes, or until hot and bubbly.