Preheat your oven to 375°F (190°C). Spray a 9×13-inch baking dish with nonstick cooking spray. In a large bowl, whisk together the cream of chicken soup, broth, and sour cream until smooth.
Stir in the uncooked rice, diced chicken, and frozen broccoli. Season with garlic powder, onion powder, and pepper, then mix in 1 cup of shredded cheddar cheese.
Pour the mixture into the prepared baking dish and spread it evenly.
Cover the dish tightly with foil and bake for 45-60 minutes. Check at 45 minutes—if the rice is still too firm, continue baking for another 5-10 minutes until the rice is tender and the liquid is mostly absorbed. Don’t overbake or the rice will get mushy—if the rice is tender and most of the liquid is absorbed, it’s ready!
Once the rice is tender, fluff the mixture with a fork and stir the casserole gently. Season with salt and pepper if needed. Sprinkle the remaining 1 cup of cheddar cheese on top.
Return to the oven for a few more minutes until the cheese is melted and bubbly. Let the casserole stand for 5 minutes before serving. Garnish with fresh parsley if desired.
Let the casserole stand for 5 minutes before serving. Garnish with fresh parsley if desired.