Preheat oven to 170°C fan assisted or 190°C without a fan (gas
5).
Remove the chicken from the packaging and rub with a little
schmaltz and sea salt.
In a flameproof casserole dish over a low heat, slowly crisp
the chicken skin side down until rich and golden then set
aside.
In the same dish, soften the onion and garlic over low heat for
3 to 4 minutes, cover with the rice, leeks and the chicken stock.
Check the seasoning, then sit the chicken on top of the rice skin
side up. Cover with a lid and cook in centre of the oven.
After 30 minutes, remove the lid and dot the garlic butter over
the rice and continue to cook uncovered for another 15 to 20
minutes until the rice is tender and moist, the chicken crisp and
thoroughly cooked.