Heat oven to 200°C (conventional).
Remove excess fat and score the top side of lamb, approximately 1cm deep.
Arrange onions and celery in the base of a roasting pan. Combine apple cider vinegar with water and pour over the vegetables.
Place meat on top of the vegetables, scored side up. Rub the meat with the spice and olive oil, being sure to get into all crevices. Place sliced garlic and fresh rosemary into the incisions. Season with salt and cracked black pepper.
Cover the roasting pan tightly with foil (this is important so it does not dry out). Place on the middle rack of the oven and immediately turn the heat down to 130°C.
Cook for 4.5 hours then remove foil and increase oven temperature to 180°C. Add the halved figs and continue cooking for another 30 minutes.
Rest for 20 minutes before serving.