Preheat the oven to 350°F (175°C).
In a large skillet, brown the ground beef and onion over medium heat.
Drain off any excess grease from the skillet.
Stir in the mixed vegetables, cream of mushroom, and cream of chicken soups, garlic powder, paprika, salt, and pepper.
Spread the beef mixture evenly in a greased 9x13-inch baking dish.
Top the beef mixture with shredded cheddar cheese.
Arrange the tater tots in a single layer on top of the cheese.
Bake in the preheated oven for 45 minutes or until the tater tots are golden brown.
Let the casserole cool for a few minutes before serving.