Wipe the meat, remove the skin and superfluous fat and cut meat into small cubes. Dip the cubes in the seasoned flour and place in a pie-dish, piling them higher in the centre. Peel and finely chop the onions; sprinkle them between the pieces of meat. Sprinkle any remaining seasoned flour between the meat. Add enough stock or water to quarter fill the dish. Roll out the pastry ¼–½ in. thick to the shape of the pie-dish, but allow an extra 2 in. all round. Cut a strip about ¾ in. wide from around the edge of the pastry to cover the rim of the pie-dish. Damp the rim, place the strip of pastry around with the cut side out and allow it to overlap the rim a little. Damp the join and the rest of the pastry and cover with the pastry lid. Press the edges lightly together. Trim, make a small round hole in the centre of the pie, and decorate with pastry leaves. Brush with beaten egg or milk. Place in a hot oven (450° F., Gas 8) until pastry is set and then reduce heat; if necessary place the pie on a lower shelf and cover with greased paper to prevent pastry becoming too brown. Heat the stock. Make a hole in the pie and pour in the hot stock before serving.