01 - In a freezer-safe baking dish, mix together the shredded chicken, uncooked white rice, cream of mushroom soup, chicken broth, frozen peas, diced onions, and season lightly with salt and black pepper.
02 - Evenly sprinkle the shredded cheddar cheese over the mixed ingredients.
03 - Securely cover the baking dish with aluminum foil and place in the freezer until ready to bake.
04 - Preheat the oven to 375°F (190°C). Transfer the covered casserole straight from the freezer to the oven and bake for 60–70 minutes, or until the rice is tender and the casserole is bubbling throughout.