Lamb cooked on the barbecue is always something but this marinade creates an even more tasty dish than usual. I like to accompany tandoori lamb with pilau rice (hot or cold) which is easily prepared in advance, irate (cucumber and yoghurt sauce) and barbecued wedges of tandoori bread. In this recipe I use best end of lamb fillet but neck fillet or a couple of racks of lamb will also work well (leg of lamb will also work but it will take 1-1 1/2 hours of slow cooking on the barbecue with the lid over or in an oven).