In a large mixing bowl, combine the cooked chicken, cream of mushroom soup, sour cream, shredded cheddar cheese, frozen peas, and cooked rice. Mix well.
Transfer the mixture to a baking dish and spread it out evenly.
In a small bowl, mix the crushed crackers with the melted butter. Sprinkle this mixture over the top of the casserole.
Bake in the preheated oven for 45 minutes, or until the top is golden brown and the casserole is heated through.
Let it cool for a few minutes before serving. Enjoy!
Notes:
This casserole is great for using up leftover chicken or turkey. You can also add other vegetables like carrots or green beans.