Preheat your oven to 375°F (190°C) to ensure it’s hot and ready for the casserole.
In a skillet over medium heat, add the ground beef and cook until browned, breaking it apart with a wooden spoon as it cooks. This should take about 5-7 minutes.
In a large mixing bowl, combine the browned beef, tomato juice, oatmeal, beaten egg, onion salt, salt, and pepper. Mix well until everything is evenly combined.
Grease your 9x13 inch baking dish lightly with cooking spray or a bit of oil. Spread the beef mixture evenly in the bottom of the dish.
Pour the can of cheddar cheese soup over the beef mixture, spreading it out evenly to cover the beef.
Arrange the tater tots on top of the cheese soup, making sure to cover the entire surface. This will create a delightful crispy topping as it bakes.
Place the casserole in the preheated oven and bake for about 30-35 minutes, or until the tater tots are golden brown and crispy.
Once baked, remove the casserole from the oven and let it cool for a few minutes before serving. This dish is best enjoyed warm and can be garnished with fresh herbs if desired.