1. Preheat the oven to 350°F 175°C and lightly grease a 9×13 inch baking dish with cooking spray or butter.

2. If needed cook the white rice according to package directions and let it cool slightly so it is fluffy and not wet.

3. Prepare the chicken by shredding or dicing cooked chicken breasts thighs or rotisserie chicken into bite sized pieces.

4. Lightly steam the broccoli florets until they are bright green and crisp tender then drain well so they do not water down the casserole.

5. In a large mixing bowl whisk together the cream of chicken soup sour cream mayonnaise and milk until completely smooth and creamy.

6. Add the garlic powder onion powder paprika salt and black pepper to the bowl and whisk again then taste the sauce and adjust seasoning if needed.

7. Fold the cooked rice chicken and broccoli into the creamy sauce until everything is evenly coated and the mixture looks thick but spoonable.

8. Stir in 1.5 cups of the shredded sharp cheddar cheese reserving the remaining 0.5 cup for the top of the casserole.

9. Transfer the mixture to the prepared baking dish and spread it into an even layer all the way to the corners.

10. Sprinkle the remaining 0.5 cup shredded cheddar evenly over the surface of the casserole.

11. In a separate bowl stir together the lightly crushed cornflakes melted butter and grated Parmesan until the cornflakes are well coated.

12. Scatter the buttery cornflake mixture evenly over the top of the cheese layer covering as much of the surface as possible.

13. Place the baking dish in the preheated oven and bake for 30 to 35 minutes until the casserole is hot and bubbly around the edges and the topping is golden brown.

14. Remove the casserole from the oven and let it rest for about 10 minutes so it can set and slice more neatly.

15. Serve warm straight from the baking dish and garnish with chopped fresh parsley or chives if you like.