In a large skillet, heat the olive oil over medium-high heat. Season the chicken breasts with salt, pepper, garlic powder, and onion powder. Add the chicken to the skillet and cook for about 5-7 minutes on each side, until golden brown and cooked through. Remove the chicken from the skillet and set aside.
In the same skillet, add the rice and toast it for about 2 minutes, stirring frequently. Pour in the chicken broth, cream of chicken soup, and milk. Stir until well combined.
Add the frozen mixed vegetables, thyme, and paprika to the skillet. Bring the mixture to a simmer, then reduce the heat to low. Place the chicken breasts back into the skillet, nestling them into the rice mixture.
Cover the skillet with a lid and cook on low heat for 20-25 minutes, or until the rice is tender and has absorbed most of the liquid. If desired, sprinkle the Parmesan cheese over the top during the last few minutes of cooking.
Remove from heat and let it sit for 5 minutes before serving. Fluff the rice with a fork and serve the chicken with the creamy rice mixture.