Directions: Put the garlic, ginger, cumin, paprica,saffron, a little salt and 1/4 teaspoons pepper in a large flameproof casserole. Mix together. Add the chicken and rub it well inside and out with the spice mixture.
Add the onions and herbs. Half cover with water (about 850mL) and drop in the cinnamon stick. Bring to the boil over a medium-high heat, then add the oil and butter. Cover and simmer for 45 minutes, or until chicken is cooked.
Transfer the chicken to the plate and keep warm. Discard the cinnamon stick. Boil the broth uncovered for a further 10 minutes, stirring regularly, until concentrated. Add the lemon juice, preserved lemon peel and olives and simmer for a few more minutes.
About 5 minutes before the sauce is ready, cut the chicken neatly into 8 pieces, remove the skin if you like, then return to the pan, turning the pieces carefully in the sauce. Taste and adjust the seasoning if necessary. Transfer to a serving dish and serve very hot.