Preheat oven to 375°F. Grease a 9x13 casserole dish.
In a large skillet, cook onion and beef until onion is translucent and beef is browned. Drain.
Meanwhile, mix together soups, garlic powder, Italian dressing mix, vegetables, ½ cup cheese, and salt and pepper if using. Add onion and beef once cooked and mix through.
Add to casserole dish and spread along the bottom. Arrange tater tots on top of meat mixture. Sprinkle with cheese.
Bake 35-40 minutes, until bubbling and cheese is browned.
Notes
*I love the cheesy flavor of the broccoli and cheese soup, but any condensed cream soup will work.