Preheat your oven to 350°F (175°C).

In a large bowl, combine the cream of chicken soup, cream of mushroom soup, water, and uncooked instant rice. Stir well to ensure everything is properly mixed together.

Transfer your creamy rice mixture into a greased 9×13 inch casserole dish. Spread it out evenly to ensure uniform cooking.

If you choose, stir in frozen vegetables or shredded cheese at this stage.

Place the raw chicken breasts on top of the rice mixture. If the breasts are particularly thick, butterfly them to ensure they cook evenly.

Sprinkle the onion soup mix evenly over the chicken before placing it in the oven.

Cover the dish tightly with aluminum foil and bake for 60 minutes.

After an hour, carefully remove the foil to check for doneness; the chicken should be cooked to an internal temperature of 165°F (75°C) and the rice tender and creamy.

For an appealing, golden-brown top, you may choose to broil the casserole uncovered for about 3 to 5 minutes.

Allow the dish to rest for 5 to 10 minutes before serving.