1. Remove all traces of fat and the white membrane from the meat.
2. Prick the meat thoroughly with a sharp knife for large fork so that the fibers are completely broken up.
3. It should virtually be falling off the bone.
4. Place in a deep baking dish or a roasting tin.
5. Soak the poppy seeds and the grated coconut in a little warm water.
6. Place the drained poppy seeds and coconut and the next 12 ingredients in a food processor of blender and blend to a smooth paste. Pour the paste over the meat and coat well all over.
7. Again, prick the meat very well all over to help the ground mixture to penetrate.
8. In another bowl, mix together the yogurt and remaining ingredients.
9. Spread this paste over the leg of lamb.
10. Put the lamb in the baking dish or roasting tin in a 170oC (325oF) mark 3 oven and, basting frequently, roast for about 2 1/4 hours. Make sure that you turn the leg over once, halfway during cooking time.
11. Remove from the oven, transfer to a heated dish.
12. Carve and serve hot.