For herb sauce, blend together half fruit juice and half oil with remaining ingredients. Add more juice and oil until its thick but pourable. Chill. Preheat oven to 240C/475F/Gas Mark 9. In a large frying pan, dry-fry the lamb to seal, then season. Place the unpeeled garlic cloves in a roasting tin with lamb on top. Roast for 30 minutes. Remove tin from oven, turn lamb over and arrange anchovies on top. Pour water into tin, return to oven for 20 minutes. Remove from oven and place meat on a plate. Stir juices in the tin. If liquid has reduced to almost nothing, add more water. Remove garlic, keep warm. Return meat to tin, place in oven but turn it off. Leave for 20 minutes. Remove, place meat on a plate with garlic. Pour juices into a saucepan and whisk in butter. Strain through a fine sieve over meat. Serve herb sauce separately. Source: Keith FLoyd, Sunday Magazine