Preheat the oven to 350°F.
In a large skillet over medium heat, cook the ground beef until browned. Drain any excess fat.
Add the diced onion and minced garlic to the skillet and sauté until the onion is translucent, about 5 minutes.
In a large mixing bowl, combine the thawed hash browns, cream of mushroom soup, sour cream, salt, black pepper, and paprika.
Stir in the cooked beef mixture and half of the cheddar cheese.
Pour the mixture into a greased 9x13-inch baking dish. Spread evenly and top with the remaining cheddar cheese and mozzarella cheese.
Bake in the preheated oven for 30-35 minutes, or until the cheese is bubbly and golden brown.
Let it cool for 5 minutes before serving. Garnish with chopped parsley if desired.
