In a large mixing bowl, combine the shredded chicken, frozen mixed vegetables, cream of chicken soup, milk, shredded cheddar cheese, cooked rice, salt, and black pepper. Mix well.
Transfer the mixture to a baking dish and spread it out evenly.
Bake in the preheated oven for 45 minutes, or until the casserole is bubbly and the top is golden brown.
Let the casserole cool for a few minutes before serving. Enjoy!
Notes:
This chicken casserole is a great way to use up leftover chicken and can be customized with your favorite vegetables.