Preheat the oven to 350°F (180°C).
In a 10x15-inch (25x35 cm) baking dish, spread the chopped onion and minced garlic. Place the butter in the center and bake for 12–15 minutes, or until softened and fragrant. Stir once or twice if browning too quickly.
While the onion mixture bakes, combine all Chicken Rub ingredients. Season both sides of the chicken thighs with the spice mix.
Remove the dish from the oven and stir in the uncooked rice.
Arrange the seasoned chicken on top of the rice, then pour the hot chicken broth and hot water around the chicken (not over it).
Cover the dish tightly with foil and bake for 30 minutes.
Remove the foil, spray the chicken with oil (optional), and bake uncovered for another 20 minutes, or until the rice has absorbed the liquid and the chicken is golden.
Let the dish rest for 5 minutes. Remove the chicken and fluff the rice with a fork. Garnish with fresh parsley or thyme if desired. Serve warm.
Notes
Chicken substitutions:
Drumsticks can be used with skin on, no time adjustment needed.
For boneless, skinless thighs or chicken breasts: Bake the rice covered for 30 minutes first, then add chicken and bake uncovered for 20–25 minutes.
Rice options:
Long-grain white rice yields the fluffiest results.
Jasmine or basmati work with the same timing.
Brown rice: Use an additional ½ cup hot water and bake covered for 1 hour, then uncovered for 15 minutes.
Avoid using minute rice, risotto, or paella rice.