Preheat the oven to 400°F (200°C) and lightly grease a 9x13-inch baking dish.
In a large mixing bowl, combine the shredded chicken, Alfredo sauce, garlic powder, and black pepper until well mixed.
Spread the chicken mixture evenly into the bottom of the prepared baking dish.
Sprinkle 1 cup of the mozzarella cheese over the chicken mixture.
Arrange the frozen tater tots in a single, even layer across the top of the cheese.
Bake for 20 minutes in the preheated oven.
Remove the dish from the oven and sprinkle the remaining 1 cup of mozzarella and the parmesan cheese over the tater tots.
Return to the oven and bake for an additional 10 to 15 minutes until the tater tots are golden brown and crispy.
Garnish with dried parsley and allow to rest for 5 minutes before serving.