Preheat your oven to 350°F (175°C).
In a large mixing bowl, combine the cream of chicken soup, milk, garlic powder, onion powder, paprika, salt, and pepper. Mix well.
In the prepared baking dish, layer the cooked rice evenly across the bottom.
Arrange the chicken breasts on top of the rice, then spread the broccoli, carrots, and mushrooms evenly over the chicken.
Pour the soup mixture over the top, ensuring all ingredients are covered.
Sprinkle the shredded cheddar cheese uniformly over the mixture.
In a small bowl, combine breadcrumbs and olive oil until the breadcrumbs are coated. Sprinkle this mixture over the cheese layer.
Cover the baking dish with aluminum foil and bake in the preheated oven for 25 minutes.
After 25 minutes, remove the foil and bake for an additional 15 minutes, or until the chicken is cooked through and the breadcrumbs are golden brown.
Let the casserole rest for 5-10 minutes before serving.