In a large skillet over medium-high heat, cook the ground beef (or turkey) until browned, breaking it up with a spatula as it cooks. Drain excess fat if necessary.
Add the diced onion and minced garlic to the skillet. Sauté for about 3-4 minutes until the onion becomes translucent.
Stir in the taco seasoning, cumin, black beans, corn, and diced tomatoes with their juice. Cook for another 5 minutes until everything is heated through. Season with salt and pepper to taste.
In a large mixing bowl, combine the cooked rice and salsa. Pour this mixture into the skillet with the meat and vegetable mixture. Stir well to combine.
Spread half of the mixture into a greased 9x13 inch casserole dish. Sprinkle 1 cup of shredded cheese over the top.
Layer the remaining mixture over the cheese, then top with the remaining cup of shredded cheese.
Cover the casserole dish with foil and bake for 25 minutes. Remove the foil and bake for an additional 10-15 minutes, or until the cheese is bubbly and golden.
Remove from the oven and let it sit for 5 minutes before slicing. Garnish with fresh cilantro before serving.
Notes
Feel free to substitute ground turkey for a lighter option.