1) Preheat oven to 375°F, 200°C, Gas 7. 2) Cook potatoes in a pan of salted water until tender, and drain. 3) Roughly mash potatoes and set aside to cool. 4) In a large frying pan, sauté pork over a medium heat until browned. 5) Add onions, carrots and seasonings and sauté until tender, about 10 minutes. 6) Add cider and water and bring up to a simmer for about 15 minutes, until most of the liquid has been absorbed. 7) Remove from heat, stir in potatoes and cool to room temperature. 8) Roll out ¾ of the pastry dough, to a thickness of approximately ½cm and line a 20cm flan tin. 9) Fill with the cooled pie filling mixture. 10) Roll out the remaining pastry and cover the pie. 11) Trim the edges and press together to seal. Cut a hole in the centre of the pie lid to allow steam to escape. Decorate with any leftover pastry. 12) Mix the egg and milk together and brush over the pie to glaze. 13) Bake in the oven for 30-40 minutes, until golden brown. 14) Traditionally served at Christmas but served cold it would be great for a summer picnic.