Preheat your oven to 375°F (190°C) and lightly grease a 9x13-inch baking dish with non-stick cooking spray.
In a large mixing bowl, combine the shredded chicken, rinsed black beans, drained corn, and the undrained can of diced tomatoes with green chiles. Stir until the ingredients are evenly distributed.
Spread the uncooked rice in an even layer across the bottom of the prepared baking dish. Sprinkle the taco seasoning evenly over the rice. Carefully pour the chicken broth over the rice and seasoning.
Spoon the chicken and vegetable mixture evenly over the top of the rice and broth, spreading it into a uniform layer. Do not stir the contents of the baking dish.
Cover the baking dish tightly with aluminum foil and bake in the preheated oven for 55 to 65 minutes, or until the rice is tender and has absorbed most of the liquid.
Remove the casserole from the oven, take off the foil, and sprinkle the shredded cheese evenly over the top. Return the dish to the oven, uncovered, and bake for an additional 5 minutes, or until the cheese is fully melted and bubbly.
Let the casserole stand for 5 to 10 minutes before serving to allow the layers to set. This will make it easier to cut into neat portions.
Serve warm, topped with a dollop of sour cream and a sprinkle of fresh chopped cilantro.
