Autumn Lamb with Blackberries and Honey

Preheat the oven to Gas mark 4-5, 180-190°C, 350-375°F.  Place the lamb on a chopping board and make several slits all over the joint.   Season. Divide the rosemary into smaller sprigs and use to stuff the joint with the garlic. Put the onions in a large non-stick roasting tin and place the joint on top of the onions, arrange the potatoes around the joint and toss in the olive oil and white wine.  Open roast for the preferred calculated cooking time, basting occasionally with any meat juices, tossing the potatoes if necessary. In a small bowl mix together the blackberries, honey, lime zest and juice, gently mash and set aside. One hour before the end of the cooking time smear the blackberry mixture over the joint and return to the oven. Cover the joint with foil during cooking if browning too quickly. Remove the joint and vegetables from the oven, transfer to a warmed plate, wrap loosely in foil and allow to rest for 10-15 minutes.