heat 4 tbsp oil in a frying pan and fry the onion with the crushed garlic until nice and golden. Add the cinnamon, cumin and seasoning.remove from heat and add the dates and preserved lemons and coriander leaves.
Stuff the lamb where there was the bone then secure with tooth picks.
preheat oven to 200°C make small incisions in the lamb and poke in the garlic slivers.
Mix 2 tbsp olive oil with the turmeric, honey, soy, a pinch of cinnamon and seasoning then rub into lamb. put in a roasting pan.
Roast 1 hour 20 minutes to 2 hours , basting from time to time.
Cover loosely and let rest 15 minutes in a warm place.