Preheat oven to 350°F (175°C). Lightly grease a 9×13-inch baking dish.

In a large skillet over medium heat, cook ground beef until browned. Drain grease.

In a bowl, combine the cooked beef, drained green beans, cream of mushroom soup, milk, garlic powder, onion powder, salt, and pepper.

Place a single layer of frozen tater tots in the baking dish. Spread half the beef mixture over the tots, then sprinkle with half the cheddar cheese.

Add a second layer of tater tots, then the remaining beef mixture, and finally the remaining cheese.

Bake uncovered for 40-45 minutes, until the casserole is bubbly and the tater tots are crisp.

Let rest for a few minutes before serving.