Preheat the oven to 375°F (190°C).
In a large skillet over medium heat, combine the broccoli florets and cauliflower rice. Sauté for about 5 minutes until they are slightly softened.
In a mixing bowl, combine the sautéed vegetables, cooked chicken, cream of chicken soup, chicken broth, garlic powder, onion powder, black pepper, salt, and paprika. Stir until well mixed.
Transfer the mixture to a greased baking dish and spread evenly.
Sprinkle the shredded cheddar cheese evenly over the top of the casserole.
If using breadcrumbs, sprinkle them over the cheese for an added crunchy topping.
Cover the baking dish with aluminum foil and bake for 30 minutes.
After 30 minutes, remove the foil and bake for an additional 15 minutes, or until the cheese is bubbly and golden brown.
Remove from the oven and let it sit for 5 minutes before serving.