Yummy (but not the healthiest =\) Hash brown casserole!

Ingredients 

1/4 cup butter, plus more for dish
1 onion, chopped
1 (16-ounce) container sour cream (I used reduced fat)
1 (10 1/2-ounce) can cream of chicken soup
1 (8-ounce) package shredded Cheddar and Monterey Jack cheese blend
1/2 teaspoon garlic powder
1 (30-ounce) package frozen shredded hash brown potatoes, thawed
1 teaspoon salt
1/2 teaspoon ground black pepper
2 cups crushed corn flakes

Directions

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 chicken soup, cheese, garlic powder, hash browns, and salt and pepper. Combine until well blended.

Pour mixture into prepared baking dish. Top evenly with crushed corn flakes mixed with butter and bake for 45 minutes, or until hot and bubbly.