100mlpork stockchicken stock can also be used so long as when cold it is set like jelly
Heat the oven to 160°C/140°C fan/gas 3. In a large bowl mix together all the ingredients for the filling.
To make the pastry, put the flour in a large bowl, then put the lard (I use saved rendered pork fat) and water into a small pan and heat gently until the lard melts. Bring just to the boil and then stir into the flour using a wooden spoon. When the mixture is cool enough to handle, (it should still feel very warm) knead well until smooth.
Cut off ¼ of the dough, wrap in cling film and reserve for the lid. Roll out the remaining dough to a circle and then place in the base of a 15 cm round cake tin. Work quickly while the dough is warm and pliable, press the dough evenly over the base and up the sides of the tin. Make sure there are no holes. Fill with the meat mixture and pack down well. Roll out the dough for the lid. Place on top of the pie. Pinch all around the edge to seal the pie. Make a hole for steam in the centre, using the handle of a wooden spoon.
Cook in the oven for 30 mins then reduce the heat to 140°C/120°C fan/gas 2 and cook for 60 minutes. The liquid bubbling out of the steam hole in the lid should be clear. Brush the top with beaten egg and return to the oven for a further 10 mins. Brush for a second time with beaten egg, turn the oven up to 180°C/160°C fan/gas 4 and cook for a further 10 minutes. Remove from oven and leave until cold.
Warm the stock gently to room temperature or just enough to get the stock able to pour. Use a small funnel to pour the stock into the pie through the hole in the top. Pour in a little at a time allowing a few seconds before each addition. Place in the fridge to set overnight.