In a medium bowl, combine olive oil, smoked paprika, dried oregano, garlic powder, salt, and pepper to create a rich marinade. Add the chicken thighs to the bowl, coating them evenly with the marinade blend. Let the chicken marinate for at least 15 to 30 minutes at room temperature.

In a large baking dish, combine diced onion, minced garlic, olive oil, melted butter, hot chicken or vegetable stock, and water. Stir in the uncooked long-grain white rice and ensure everything is well combined.

Carefully arrange the marinated chicken thighs over the rice mixture, slightly embedding the chicken into the rice.

Cover the baking dish tightly with aluminum foil and place it in the preheated oven at 350°F (175°C). Bake for 30 minutes.

After 30 minutes, remove the foil and spray the dish lightly with oil. Return it to the oven, uncovered, and bake for an additional 30 minutes.

For an extra crispy finish, broil for 2-3 minutes until the chicken skin reaches your desired level of crispiness.

Once done, remove the dish from the oven and let it rest for about 10 minutes, allowing the juices to redistribute. Fluff the rice gently with a fork and serve.