Preheat the oven to 375°F (190°C). Position a rack in the center of the oven for even baking.

In a skillet over medium heat, brown the ground beef until fully cooked. Break the meat into small pieces as it cooks, then drain any excess fat.

In a large bowl, combine the cooked beef with drained green beans, cream of mushroom soup, milk, garlic powder, and onion powder. Stir until evenly coated and the soup and milk form a smooth sauce.

Spread the mixture evenly in a 9×13 inch baking dish. Smooth the top so the Tater Tots will sit evenly.

Sprinkle shredded cheddar cheese on top and arrange Tater Tots in a single layer. Place the tots close together to form a continuous golden crust.

Bake for 30 to 35 minutes, until Tater Tots are golden brown and filling is bubbly. Tent the dish loosely with foil if the tots are browning too quickly.

Allow to cool for a few minutes before serving to let the filling set.