Preheat your oven to 375°F (190°C).
In a skillet, cook the ground beef over medium heat until browned. Drain any excess fat.
Add the taco seasoning and water to the beef. Stir and let it simmer for a few minutes.
In a large bowl, combine the cooked beef, uncooked rice, black beans, corn, diced tomatoes, and half of the shredded cheese.
Transfer the mixture to a baking dish and cover with foil.
Bake in the preheated oven for 30 minutes.
Remove the foil, sprinkle the remaining cheese on top, and bake for an additional 10-15 minutes, or until the cheese is melted and bubbly.
Let it cool for a few minutes before serving. Enjoy!