Preheat your oven to 375°F (190°C).

In a large skillet, add 1 pound of ground beef over medium heat. Stir occasionally for about 5-7 minutes until browned. Add 1 diced onion and cook for an additional 3-4 minutes.

Reduce heat to low and stir in a can of cream of mushroom soup and a half-cup of sour cream until mixed.

Grease a 9x13-inch casserole dish and spoon the creamy beef mixture into the bottom.

Sprinkle 1 cup of shredded cheddar cheese over the beef mixture. Place frozen tater tots in a single layer on top.

Bake for 25-30 minutes until tater tots are golden and crispy.

Sprinkle an additional cup of cheddar cheese over the tater tots and bake for another 5 minutes.

For an extra crispy finish, turn on the broiler for 1-2 minutes. Allow the casserole to cool for 5 minutes before serving, and garnish with chopped green onions.