Preheat the Oven: Set it to 350°F (175°C). Grease a 9×13 inch casserole dish with butter to prevent sticking.

Prepare the Base Mixture: In a large bowl, mix the cream of chicken soup, cream of mushroom soup, water, and uncooked instant rice. Stir until combined.

Pour into the Baking Dish: Transfer the mixture into the greased casserole dish, spreading it evenly.

Add Optional Ingredients: If desired, stir in frozen vegetables or shredded cheese for an extra flavor kick.

Top with Chicken: Place the raw chicken breasts on top of the rice mixture. If your chicken is thick, consider butterflying for even cooking.

Sprinkle Soup Mix: Evenly sprinkle the onion soup mix over the chicken to enhance the flavor profile.

Cover and Bake: Tightly cover the dish with aluminum foil and bake for 60 minutes. Avoid lifting the foil during cooking to trap moisture.

Check for Doneness: After an hour, remove the foil. Ensure the chicken is fully cooked (reaching an internal temperature of 165°F/75°C) and that the rice is tender and creamy.

Optional Broil: For a golden finish, broil the casserole uncovered for 3–5 minutes until lightly browned.

Let Rest and Serve: Allow the casserole to rest for 5–10 minutes before serving to make it easier to dish out.