In a large skillet, fry the onion in the oil until it is soft and translucent. Add in the ground beef, fry until completely cooked through. Drain the fat, mix the garlic. Fry until golden, around 2-3 minutes, then add some salt and pepper to taste and transfer to a 9x13 baking pan or oven safe pan of equivalent size.
Combine the vegetables and the soup. Pour over top of the hamburger. Sprinkle the cheese on top evenly.
Place the tater tots in an even layer on top of the soup mixture.
Bake in the oven for 50-60 minutes or until the tater tots on top are crispy and browned. Remove from the oven and serve.
You can change up the soups that you use in the mixture if you are bold!
You can also sprinkle MORE cheese on top at the end and let it melt in the oven if you wanted cheesy tater tot casserole.