Make the pastry by putting dripping and ½ pint of water in a saucepan. Bring to the boil. Sieve flour and salt, make well in the centre and pour in the hot liquid.
Mix to a dough with a knife, then knead on a floured board till free of cracks. Cut off a quarter of the pastry and keep it warm. Line six small tins or shape some cases round the base of a glass.
Cut the mutton into small pieces and mix with the chopped onion. Add the seasoning. Use a little stock to moisten and fill the pies, put on the lids, wetting the edges and sticking them firmly together. Make a hole in the top of each. Brush the pies with a little beaten egg. Bake in a moderate oven for 40 minutes. Serve hot, filling them up with a little hot gravy.