Cook the ground beef: In a large skillet, heat olive oil over medium-high heat (if using lean ground beef). Add ground beef and cook, breaking it apart, until browned and cooked through, about 6-8 minutes. Drain excess fat if needed.

1. Sauté the onion and garlic: Add diced onion to the skillet with the beef and cook for 3-4 minutes until softened. Add minced garlic and cook for another 30 seconds until fragrant.
2. Season the beef: Add taco seasoning, salt, and pepper. Stir to coat the beef evenly. Add a splash of water if needed to help coat the beef with seasoning.
3. Add the beans and corn: Stir in black beans and corn, cooking for 2-3 minutes until heated through.
4. Add the rice: Stir in cooked rice and mix everything together. Let it cook for an additional 2-3 minutes to combine the flavors.
5. Top with cheese: Sprinkle shredded cheese over the mixture and cover the skillet with a lid. Cook for 2-3 minutes until cheese is melted and bubbly.
6. Serve: Garnish with fresh cilantro and add your favorite toppings, such as sour cream, salsa, or guacamole. Serve immediately.