Sear the chicken: Pat the chicken thighs dry with paper towels and season generously with salt, pepper, and 1/2 teaspoon of the smoked paprika. Heat the oil in your oven-safe skillet over medium-high heat until it shimmers. Place the chicken skin-side down and cook without moving for 5–7 minutes, until the skin is deep golden brown and releases easily from the pan. Flip and cook for 3 more minutes. Transfer the chicken to a plate.
Cook the aromatics: Reduce the heat to medium. Add the diced onion to the pan and cook, stirring occasionally, until it is soft and translucent, about 5 minutes. Add the minced garlic and cook for 30 seconds until fragrant.
Deglaze and build the sauce: Pour in about 1/2 cup of the warm chicken stock, using a wooden spoon to scrape up all the browned bits from the bottom of the pan. Stir in the remaining stock, the heavy cream, the rest of the smoked paprika, and the dried thyme. Bring the mixture to a gentle simmer.
Add the rice: Stir in the long-grain rice. Make sure it is evenly distributed in the liquid. Season the sauce with a little more salt and pepper.
Nestle the chicken back in: Place the seared chicken thighs back into the skillet, skin-side up, nestled into the rice and sauce. The skin should be above the liquid to stay crispy.
Bake: Cover the skillet tightly with a lid or aluminum foil. Transfer to the preheated oven and bake for 40–45 minutes, until the rice is tender and has absorbed most of the liquid, and the chicken is cooked through and beginning to fall apart.
Rest and serve: Remove the skillet from the oven and let it rest, covered, for 10 minutes. This allows the rice to finish absorbing the steam and the sauce to settle. Garnish with fresh parsley and serve directly from the skillet.