While chicken is in the oven, make the rice. Heat the olive oil in a medium saucepan over medium high heat and once hot, add the onion wedges, chicken backbone and wing tips. Stir around until onion browns, then add the water. Let it boil, then reduce heat to a simmer and let it simmer while the chicken cooks for 45 minutes. If you start this before the chicken, you can simmer for longer! You can add any aromatics (bay leaves, cinnamon stick, cloves), but we kept the recipe very straightforward.
Strain the stock and discard the onion and bones, then add the soaked and drained basmati rice to the stock. Top up with additional water if needed, until water comes about 1 inch above the rice. Season with salt, bring rice to a boil, then once it boils cover with a tight fitting lid. Reduce heat to low and simmer for 20 minutes or until all the water has been absorbed.
Remove the rice from the heat, let it stand for 10 minutes, then fluff with a fork. Place rice on serving platter and top with the cooked chicken.