Preheat the oven to 350°F (175°C) and grease a baking dish.

In a saucepan, combine whole milk or half and half with deli white American cheese over medium heat until melted and smooth.

Stir in the chive and onion cream cheese into the melted cheese mixture.

Add fire-roasted green chiles, garlic salt, and onion powder to the sauce.

In a bowl, combine thawed hash browns with the cheese sauce.

Spread the mixture into the baking dish, top with Monterey Jack cheese and dot with butter.

Bake for 45-50 minutes until golden brown and bubbling.

Let cool for 5-10 minutes before serving.