Preheat oven to 220c/425f/Gas 7. 1 Make slits in the chunks of lamb with a small knife and push in slivers of garlic, using up about a third of them. Brown the lamb chunks, two or three at a time, in a third of the oil over a high heat. 2 As they brown, put into a large oiled roasting tin or ovenproof dish. Nestle the heads of garlic and rosemary and thyme sprigs amongst them, and scatter over the remaining slivered garlic. Drizzle the remaining oil over the lot. 3 Roast in the hot oven for 20 minutes and pour over the sherry. Season generously with salt and pepper and cover the dish tightly with foil. 4 Return to the oven and reduce the heat to 180c/350f/Gas 4. Roast for another 3 1/2-4 1/2 hours, basting frequently with the pan juices. 5 If the pan threatens to dry out, add a splash or two of hot water and make sure the foil is really covering the dish properly. 6 The lamb is done when it is so tender that a fork just slides through it like softened butter. Remove the foil, sprinkle with parsley and take to the table. 7 Give each diner a chunk of lamb and a whole head of garlic, moistened with some of the pan juices. To eat the garlic, squeeze the cloves with the flat of a knife and the softened flesh will ooze out. Either smear onto the lamp or scoop up with good bread. Recipe by: Sophie Grigsons Herbs