This one-pot dish uses whole shoulder of lamb spread with a herb butter then slow cooked for 4 hours with the addition of lamb stock, red onions, celery and butternut squash or until the meat falls away from the bone.
Preheat the oven to 170°C,150°C Fan, Gas Mark 3.
Prepare the herb butter; in a small bowl mix all the ingredients together.
Put the onions and celery in the base of a 2.8L flame/heatproof dish or roasting tin.
Put the lamb on a chopping board and lightly score the surface with a sharp knife.
Spread the herb butter over the joint and place on top of the vegetables, pour over the stock, cover with foil and transfer to the oven for 3½ hours. Remove the foil, add the butternut squash, return to the oven and continue to cook for a further 30 minutes.
Transfer the lamb and vegetables to a large platter and keep warm. Skim the fat from the dish leaving behind the meat juices.
Serve the lamb with the vegetables, meat juices and creamy mash.