Remove all bones from the lamb and dice
the meat, set aside. Put the bones in a saucepan
and add the onion, water to cover and season. Bring to a boil and simmer
for 1 1/2 hours. Strain
the stock and reserve.
Preheat the oven to 350 degrees F.
Line a pie
dish with half of the pastry
. Put in diced lamb
and parsley and season. Cover with the remaining pastry, and seal and flute
the edge. Make a small hole in the center of the pastry lid and brush with beaten egg.
Bake for 2 hours or until the pastry is golden brown. Pour the stock
through the hole in the lid, adding enough to fill the pie, and leave to cool before serving