Preheat your oven to 350°F (175°C) and grease a 9x13-inch baking dish.
In a large bowl, whisk together the cream of chicken soup, chicken broth, milk, garlic, thyme, salt, and pepper until smooth.
Spread the uncooked rice in the bottom of the prepared baking dish. Place the chicken breasts on top of the rice.
Pour the creamy soup mixture over the chicken and rice, ensuring everything is covered evenly.
Cover the dish tightly with aluminum foil and bake for 50-60 minutes, or until the rice is tender and the chicken is cooked through.
Remove the foil and sprinkle shredded cheddar cheese over the top. Bake uncovered for an additional 10 minutes, or until the cheese is melted.
Let the casserole rest for 5-10 minutes before serving. Enjoy your Creamy Chicken Rice Casserole!