Preheat the oven: Set to 375°F (190°C).
Season the chicken: Pat chicken dry. Season with salt, pepper, paprika, garlic powder, and onion powder.
Sear the chicken: Heat olive oil in an oven-safe skillet over medium-high heat. Sear chicken for 3-4 minutes per side until golden. Remove and set aside.
Cook the aromatics: In the same skillet, sauté onion for 2-3 minutes until translucent. Add garlic and mushrooms (if using) and cook for 1-2 minutes.
Add rice and liquids: Stir in rice, then add chicken broth and heavy cream (or cream of mushroom soup). Stir to combine and bring to a simmer.
Nestle the chicken: Place chicken back in the skillet, nestling into the rice mixture. Sprinkle with thyme and Parmesan, if using.
Bake: Cover skillet with a lid or foil and bake for 30-35 minutes, until rice is tender and chicken reaches 165°F (74°C).
Garnish and serve: Fluff rice with a fork, garnish with parsley, and serve hot.