Preheat oven to 400 degrees F.

Spread  hash browns in the bottom of a greased 9-in. pie plate to make a crust.

Bake crust for 15-20 minutes. Reduce heat to 350 degrees F.

Make the pie filling by combining the rest of the hash browns, half and half, butter, onion, and seasonings in a sauce pan. Stir until butter is melted and everything is well combined.

Spread filling on top of the pie crust.

Sprinkle the top of the pie with parmesan cheese.

Bake for 1 hour on 350 degrees F. or until top if fully browned.