Preheat your oven to 375°F (190°C) and grease a 9×13-inch baking dish.
- In a large bowl, combine the cream of chicken soup, sour cream, milk, garlic powder, onion powder, salt, and pepper. Stir until smooth.
- Add the shredded or cubed chicken and frozen mixed vegetables to the soup mixture. Stir until everything is evenly combined.
- Pour the chicken and vegetable mixture into the prepared baking dish, spreading it out evenly.
- Arrange the frozen tater tots in a single layer on top of the chicken mixture. Make sure they cover the entire surface of the casserole.
- Place the casserole in the preheated oven and bake for 35-40 minutes, or until the tater tots are golden brown and crispy.
- Remove the casserole from the oven and sprinkle the shredded cheddar cheese over the top. Return the casserole to the oven and bake for an additional 5-7 minutes, or until the cheese is melted and bubbly.
- Let the casserole cool for a few minutes before serving. Enjoy!