First make the pastry. Heat the lard in the milk and water in a small saucepan until melted then stir in the mustard. Mix the flour and salt in a bowl then stir in the melted lard mixture and mix to a soft ball. Cool for 10 minutes. Mix the sausagemeat, chicken, bacon, cloves, allspice and plenty of seasoning together in a bowl.
Remove one-third of the pastry and set aside. Press the remaining warm pastry over the base and sides of a deep 18 cm (7 inch) loose-bottomed cake tin. Spoon in half the filling and level. Cover with half the sage leaves, then the apple slices, then spoon over the rest of the filling. Level and top with the remaining sage. Brush the edges of the pastry with the egg glaze.
Roll the reserved pastry to a circle a little larger than the tin, arrange on the pie and press the edges together. Trim off the excess then crimp the edge. Make a slit in the top of the pie, then brush with egg glaze. Cook in a preheated oven, 180°C (350°F), Gas Mark 4, for 1½ hours, covering with foil after 40 minutes, when golden. Leave to cool, remove the tin then put the pie, still on the tin base, in the refrigerator for 3–4 hours or overnight. When ready to serve, remove the base and cut the pie into wedges.