Preheat the oven to 400°F (200°C) and lightly grease a 9×13-inch baking dish.
Rinse the rice thoroughly in a fine mesh strainer until the water runs clear.
Add the chicken broth, cubed chicken, frozen vegetables, rinsed rice, heavy cream, seasoning salt, Italian seasoning, onion powder, and black pepper to the baking dish.
Stir everything together until well combined.
Scatter the small pieces of butter evenly over the top of the mixture.
Cover the dish tightly with aluminum foil.
Bake the Cheesy Chicken and Rice Casserole for 40–50 minutes until the rice becomes tender and the chicken is fully cooked.
Remove the foil, sprinkle shredded cheese evenly over the casserole, and return to the oven for about 5 minutes until the cheese melts.
Serve warm and enjoy.