01 - Preheat oven to 375°F. Lightly grease a 9x13 inch baking dish with cooking spray or butter.
02 - In a large skillet over medium heat, cook ground beef and chopped onion until beef is browned and onion is softened, about 6-8 minutes. Drain excess fat from the skillet.
03 - Stir in garlic powder, onion powder, kosher salt, and black pepper. Cook for 1 minute to bloom the spices.
04 - Add the condensed cream of mushroom soup and milk to the skillet. Stir until fully combined and smooth.
05 - Fold in the frozen corn kernels and frozen peas until evenly distributed throughout the sauce mixture.
06 - Spread the beef and vegetable mixture evenly across the bottom of the prepared baking dish. Sprinkle shredded cheddar cheese generously over the top.
07 - Arrange frozen tater tots in a single, even layer over the entire surface of the casserole. Ensure they are tightly packed but not overlapping.
08 - Bake uncovered for 40-45 minutes until tater tots are golden brown and crispy, and the filling is bubbling around the edges.
09 - Let the casserole rest for 5 minutes before serving to allow the filling to set slightly for easier scooping.