Preheat your oven to 375°F and lightly grease a 9×13-inch baking dish.

Dice the onion, tomato and green onions, then set them aside.

Heat a large skillet over medium heat. Add the ground beef and chopped onion and cook, breaking the meat into small pieces, until the beef is no longer pink. Stir in the minced garlic and cook for 1-2 minutes, just until fragrant.

Carefully drain off any excess grease. Add the corn, black beans, enchilada sauce, Rotel, and taco seasoning to the skillet. Stir well and let the mixture simmer on low for about 5 minutes.

Spread the beef mixture evenly into the prepared casserole dish. Arrange the Tater tots in a single, even layer over the top.

Bake uncovered for 35 minutes, until the Tater tots are golden and crisp.

Remove the casserole from the oven and sprinkle the cheese evenly over the top. Return to the oven and bake for another 8-10 minutes, just until the cheese is melted.

Finish with diced tomatoes, black olives, and green onions before serving.