Preheat oven to 350°F/180°C.
Scatter onion and garlic in a baking dish (about 10 x 15" / 25 x 35 cm), then place butter in the center, just dollop it.
Bake for 15 minutes (check at 12 minutes, mix if some bits are browning too much).
Meanwhile, mix together Chicken Rub. Sprinkle on both sides of the chicken.
Remove baking dish from the oven. Add rice then mix well.
Place chicken on top of rice (snug in just a little). Then slowly pour chicken hot broth and water around but not on the chicken (don't want to wash off that rub!)
Cover tightly with foil, then bake for 30 minutes.
Remove foil, optionally spray chicken with oil spray (gives chicken nicer finish), then bake for a further 20 minutes until liquid is absorbed.
Remove from oven and let stand for 5minutes. Remove chicken and fluff up rice with a fork. (Fluffing the rice is very important to acheive the desired texture.) Garnish with parsley or thyme if desired, serve and enjoy!