Start by preheating your oven to 350 degrees Fahrenheit. While it's warming, take a 9x13-inch baking dish and lightly coat it with nonstick spray. This step takes literally two minutes, but it prevents the casserole from sticking and makes cleanup so much easier afterward. I usually spray not just the bottom but also partway up the sides.

Prepare the frozen broccoli according to package directions. This typically means boiling it for about 5-7 minutes until it's just tender but still has some structural integrity—you don't want mushy broccoli. Once it's cooked, drain it thoroughly in a colander, pressing gently with the back of a spoon to remove excess liquid. Excess water is the enemy of a good casserole because it will make everything soupy. Place the hot, drained broccoli on a cutting board. Using a sharp knife, run it through the broccoli pieces to break them into smaller, bite-sized chunks. This is important because whole florets can be a bit unwieldy in a casserole. You're aiming for pieces about the size of a grape or small walnut.

In a large mixing bowl, combine the cream of chicken soup, sour cream, and processed cheese product. Stir these together thoroughly until you have a smooth, cohesive mixture. The processed cheese will melt into the other ingredients and create a wonderfully smooth, creamy base. This should take about 1-2 minutes of stirring with a sturdy wooden spoon or whisk. The processed cheese product might seem like an unusual ingredient to a home cook, but it's actually brilliant here. Unlike block cheese, it contains emulsifiers that help it meld smoothly without becoming grainy or separated. This is why the casserole has that signature creamy texture that's so appealing.

Add the chopped broccoli, cooked rice, diced chicken, and all your seasonings (garlic powder, onion powder, salt, pepper, and smoked paprika if using) to the creamy mixture. Stir everything together thoroughly until every component is evenly coated and distributed. This is where the magic starts happening—you're building a cohesive dish where every bite will have a little bit of everything. Take a moment to taste the mixture at this point. If your chicken was previously seasoned (rotisserie chicken, for example), you might find the seasonings are already perfect. If your chicken was unseasoned, you may want to add a bit more salt or a pinch more garlic powder. This is your chance to adjust before baking.

Spoon the entire mixture into your prepared baking dish, spreading it evenly with the back of your spoon. The mixture should reach roughly the middle of the dish—don't worry if it doesn't fill it completely. Top the casserole generously and evenly with the shredded sharp cheddar cheese, using all 2 cups. The cheese will melt and create a golden, slightly crispy layer on top while the interior stays creamy. This contrast in textures is one of the things that makes casseroles so satisfying to eat.

Cover your baking dish tightly with aluminum foil. This keeps the moisture in during the initial baking phase and ensures that the interior heats through evenly without the top drying out. Place the dish in your 350-degree oven for 15 minutes. During this time, the flavors will begin melding and the casserole will heat through.

Carefully remove the foil (watch for steam!) and return the casserole to the oven for an additional 10 minutes. This is when the cheese on top will melt fully and develop that golden-brown appearance. You're looking for the cheese to be completely melted and starting to show a few golden-brown spots around the edges. The edges of the casserole should be bubbling gently. This two-stage baking method is professional technique that ensures the interior is hot throughout while the top cooks perfectly without burning.

Remove the casserole from the oven and let it rest for about 5 minutes before serving. This allows the structure to set slightly, making it easier to portion. The casserole will actually continue cooking slightly from residual heat during this resting period, which is why you don't want to overbake in the previous step. Serve while hot and steaming, and watch as your family or guests dig in with obvious satisfaction. There's something deeply rewarding about creating a dish that brings people together this way.