In a medium, oven-proof pot, saute the onion and carrot in a little olive oil until soft and translucent.
Add the lamb and allow to brown before adding the all purpose rub, red wine, stock and 4 sprigs of rosemary.
Cover the pot and place in the oven. Allow to braise for 2-3 hours until the lamb is tender and succulent.
Wrap the garlic bulb in foil and place alongside the lamb in the oven.
Allow the garlic to roast for 60-90mins until sweet and soft then remove from the oven and squeeze the juicy flesh from the papery skins.
When the lamb is cooked, remove from the oven and transfer to a suitable pie dish. Top with the roasted garlic and add another sprig of fresh rosemary.
Raise the temperature of the oven to 200°c.
Cover the lamb with the puff pastry (cut to size) and crimp edges. Cut a slit into the pastry to allow steam to escape and brush the pastry with the beaten egg.
Place the pie into the oven and allow to bake until the pastry is golden brown and crisp (approximately 30 minutes).