Preheat the oven to 350°F. Spray a 9x13-inch baking dish with cooking spray and set aside.
In a large skillet with deep sides or a dutch oven, over medium heat, add the ground beef, break it up into crumbles and cook until there is no pink left, about 10 minutes. Stir occasionally. Drain any excess grease.
Add the onions, salt, and pepper, to the pot and occasionally stir until they are softened, 8-10 minutes. Add the garlic and stir it in, cook until fragrant, 30 seconds.
Take off the heat. Stir in the frozen vegetables, cheddar soup, sour cream, and half of the cheddar. Stir until combined.
Place the filling into the prepared baking dish. Top with the remaining cheese.
Add an even layer of the tater tots on top, you may have a few leftover.
Bake for 35-45 minutes until the tater tots are golden brown and crispy. Serve immediately.
Notes
You can use any cream of something soup you prefer, I used cheddar to make this dish extra cheesy, yum!
Don't have frozen mixed veggies? You can swap them with whatever frozen veggies you like prefer. I suggest trying peas, peas and carrot, green beans, or corn. Or a combo of any of them. You can also use canned vegetables instead.
Want to try different cheese options, see some more ideas above in the FAQ section.
Feel free to use ground chicken, ground turkey, or ground pork in place of the ground beef.
If you want this more on the creamy side, add two cans of condensed soup.