Preheat your oven to 350°F (175°C).

In a large mixing bowl, combine the shredded chicken, uncooked rice, cream of chicken soup, cream of mushroom soup, chicken broth, milk, garlic powder, onion powder, and black pepper. Stir until everything is well mixed and the rice is evenly distributed.

Pour the mixture into a greased 9x13-inch baking dish and spread it evenly with a spatula.

Cover the baking dish tightly with aluminum foil to trap the steam.

Bake covered for 45 minutes, allowing the rice to cook through and absorb the liquids.

Carefully remove the foil (watch for hot steam), sprinkle the shredded cheddar cheese evenly over the top, and return to the oven uncovered.

Bake for an additional 15 minutes until the cheese is bubbly and developing golden spots.

Let the casserole rest for 5 minutes before serving to allow everything to settle.