Preheat oven to 375°F and grease a 9×13 inch baking dish.
In a large bowl, combine ground beef, diced onion, garlic, breadcrumbs, egg, ketchup, Worcestershire sauce, salt, and pepper. Mix until well combined.
Press the meat mixture into the bottom of the prepared baking dish.
In a separate bowl, mix cream of mushroom soup with milk until smooth. Pour over the meat layer.
Arrange frozen tater tots in a single layer over the soup mixture.
Bake for 35-40 minutes until tater tots are golden brown.
Remove from oven and sprinkle shredded cheese over the top.
Return to oven for 5-10 minutes until cheese is melted and bubbly.
Let cool for 5 minutes before serving.