Step 1

Preheat the oven to 350°F. In a small skillet, melt the butter over medium heat. Add the onion and saute until softened and translucent, four to six minutes. Add the garlic, and cook and stir for one minute longer. Transfer the onion and garlic to a large bowl.

Step 2

Stir in the cream of chicken soup, sour cream, Parmesan cheese, salt and pepper until blended. Add the hash browns and 1 cup of the grated cheddar cheese. Stir everything together to combine.

Step 3

Spoon the hash brown mixture into a greased 13x9-inch baking dish. Sprinkle the top with the remaining 1 cup of grated cheddar cheese. Bake the hash brown casserole, uncovered, until it's bubbly, 50 to 60 minutes. If desired, sprinkle with chives.