Preheat the Oven: Initiate by preheating the oven to a temperature of 375 degrees Fahrenheit.

Prepare the Cooking Vessel: In a large oven-safe skillet, combine the butter and olive oil. Place over a medium-high heat until the butter has melted completely.

Sauté Onions: Introduce the diced onions to the skillet and sauté for approximately 2 minutes, or until they become translucent.

Season the Chicken: In a separate dish, season the diced chicken breasts with garlic powder, sweet paprika, and onion powder.

Cook the Chicken: Transfer the seasoned chicken to the skillet and cook for about 5 minutes, turning occasionally, until the chicken is golden brown on all sides.

Incorporate Mushrooms: Add the sliced mushrooms to the skillet, season with salt and pepper to taste, and continue to cook for an additional 4 minutes, stirring frequently, until the mushrooms are soft and fully cooked.

Add Garlic: Stir in the minced garlic and cook for another minute until aromatic.

Introduce Rice: Incorporate the rice into the skillet, stirring constantly, and cook for 1 minute to lightly toast the grains.

Add Broth and Bake: Pour in the chicken broth, increase the heat to high and bring the mixture to a boil. Once boiling, remove from the stove, cover the skillet with a lid, and place it in the preheated oven. Bake for 30 minutes.

Final Cooking Stage: After the initial baking period, remove the lid and continue to bake for an additional 3 minutes or until the liquid has been fully absorbed by the rice.

Rest and Serve: Remove the skillet from the oven and allow the dish to stand for 5 minutes. Just before serving, garnish with grated Parmesan cheese and chopped fresh parsley.