Preheat your oven to 350°F (175°C).
In a large mixing bowl, combine the uncooked rice, chicken broth, heavy cream, sour cream, and cream of mushroom soup. Stir until well blended.
Add the cooked chicken, peas and carrots, garlic powder, onion powder, salt, and pepper. Mix until all ingredients are evenly distributed.

Transfer the mixture into a lightly greased 9×13-inch baking dish and spread evenly.
Sprinkle the shredded cheddar cheese over the top of the casserole.
In a small bowl, mix the panko breadcrumbs with melted butter. Sprinkle this mixture over the cheese for a crispy topping.
Cover the dish with aluminum foil and bake in the preheated oven for 30 minutes.
Remove the foil and continue to bake for an additional 15-20 minutes, or until the top is golden and crispy and the rice is fully cooked.
Let the casserole cool for a few minutes before serving. Garnish with fresh parsley if desired.
Variations & Tips
For a healthier version, you can use brown rice instead of white, although you may need to adjust the cooking time accordingly. You can also add more vegetables such as broccoli florets, sliced mushrooms, or bell peppers for extra flavor and nutrition. To cater to different tastes, consider swapping the cream of mushroom soup with cream of chicken or celery soup. For a kicking twist, add a teaspoon of red chili flakes or a dash of hot sauce for some heat.