Preheat the oven to 400 degrees Fahrenheit and spray a 9X13 baking dish with non-stick cooking spray.
Add the ground beef and diced onions to a large skillet and heat over medium high heat. Cook, breaking up the beef as it cooks, until the beef is no longer pink.
Drain any excess grease from the pan.
Stir the ketchup, mustard, Worcestershire sauce, salt, pepper and garlic powder into the pan and heat for 3-4 minutes until the sauce is heated through.
Remove the pan from the heat and stir in 2 cups of the shredded cheddar cheese. Allow the heat from the meal to melt the cheese.
Spread the beef mixture into the bottom of the prepared 9×13 baking pan.
Place one layer of tator tots on top of the beef mixture in the pan.
Baked for 25 minutes uncovered.
Sprinkle the top of the casserole with the remaining shredded cheddar cheese on top and bake for 5 more minutes until the cheese is melted.
Remove from the oven. Let the casserole sit for 10-15 minutes and then it’s ready to serve and enjoy!
Notes
Refrigerate any leftovers in an airtight container for up to 5-6 days. This casserole can be made ahead of time. Assemble the casserole but do not top with the tator tots. Cover and refrigerate for up to 1 day and then top with the tator tots before baking as written.