As you have uncooked grounded beef in your ingredients so first you have to cook your meat.
In a skillet after adding some oil cook the beef. First fry the onions and when they get soft add the beef in it.
Cook it on high heat and drain the excess oil once the beef is cooked and completely browned.
Once they both are cooked, pour the mayonnaise into the skillet. In the same step add ketchup and pickle relish to your beef.
Stir the whole mixture for it to get well combined.
Sprinkle salt and pepper to your taste.
Take the baking pan and arrange 3-4 tater tots in each cup and bake them for a few minutes. You should use a muffin pan for this purpose.
After baking for 10 minutes, remove them from the oven and press them down into cups. A tarter tot cup will be formed as a result.
Fill each tater tot with the cooked beef. Repeat the process one by one for all the tater tots.
After filling it's time to top the tots. Dress them by sprinkling shredded cheese over them.
After the whole treatment, bake the tarter tots in the oven for 15 minutes.
After baking them remove them from the oven place them on the racks to get the air-cooled.
Once cooled, get them removed from the muffin pan. While your tots are getting cooled, you should prepare the sauce.
Make the sauce and drizzle over the Cheeseburger tarter tots before serving!
Serve after topping with pickle slices and have Fun!