Preheat & Prep Tots: Preheat oven to 400°F. Spread the tater tots out in a single layer on a large baking sheet. Bake for 15 minutes.

Cook Aromatics & Beef: While the tater tots are baking, heat the olive oil in a large skillet over medium heat. Add the diced onions and sauté until softened, about 3-4 minutes. Add the minced garlic and sauté for 1 minute; do not allow the garlic to brown. Crumble the ground beef into the skillet and sauté, stirring often, until completely browned. Drain off any excess fat.

Season Meat Mixture: Add the taco seasoning and water to the meat and stir well. Simmer over medium heat for 1-2 minutes, then remove from the heat.

Combine Filling: In a large mixing bowl, combine the ground beef mixture, black beans, corn, green chiles, and enchilada sauce. Add 2 cups of the shredded cheese and stir well.

Assemble Casserole: Lightly grease a 9x13 inch glass baking dish with non-stick cooking spray. Pour the enchilada filling mixture into the dish and spread evenly. Arrange the crispy tater tots over the top in a single layer. Top the casserole with the remaining 1 cup of shredded cheese.

Bake: Reduce the oven heat to 375°F. Bake the casserole uncovered for 30 minutes or until the cheese is melted and the casserole is bubbling around the edges.

Serve: Cool the casserole slightly, then serve with the toppings of your choice.