In a large mixing bowl, combine the cooked rice, shredded cheddar cheese, sour cream, cream of chicken soup, shredded chicken, thawed peas and carrots, salt, and black pepper. Mix well.
Transfer the mixture into a greased baking dish and spread it out evenly.
Bake in the preheated oven for 45 minutes, or until the top is golden and bubbly.
Let it cool for a few minutes before serving. Enjoy!
Notes:
This casserole can be made ahead and refrigerated. Just add an extra 10 minutes to the baking time if baking from the fridge.