Preheat your oven to 350°F (175°C).
In a large skillet, brown the ground beef with the diced onion over medium heat until the beef is no longer pink, about 5-7 minutes.
Stir in the black beans, corn, cream of mushroom soup, chili powder, garlic powder, salt, and pepper until well combined.
Transfer the mixture into a greased 9x13 inch baking dish, spreading it evenly.
Sprinkle the shredded cheddar cheese evenly over the mixture.
Arrange the tater tots in a single layer on top of the cheese.
Bake in the preheated oven for 30-35 minutes, until the tater tots are golden and crispy.
Remove from the oven and let it cool for a few minutes before serving.