Begin by making the pastry by sifting the flour and pinch of salt into a large bowl, holding the sieve as high as possible.
Now add the lard and butter, cut into smallish lumps, then take a knife and begin to cut the fat into the flour. Go on doing this until it looks fairly evenly blended, then begin to rub the fat into the flour using your fingertips only and being as light as possible. As you do this, lift it up high and let it fall back into the bowl, just long enough to make the mixture crumbly with a few odd lumps here and there. Now sprinkle 1 tablespoon of water in, then, with a knife, start bringing the dough together. Then discard the knife and, finally, bring the dough together with your fingertips. When enough liquid is added, the pastry should leave the bowl fairly clean. If this hasn’t happened, then add a spot more water. Now place the pastry in a polythene bag and leave it in the fridge for 30 minutes to rest.
Pre-heat the oven to gas mark 6, 400°F (200°C) and pop the baking sheet in to pre-heat at the same time.
Next, place the chopped meats and bacon in a mixing bowl and add all the other ingredients (except the beaten egg). Now, mix them all thoroughly together, with a good seasoning of salt and pepper. Then divide the pastry in half, and roll out one half, on a lightly floured surface, to line the tin. Pile the meat mixture evenly on the pastry, dampen the edges, then roll out the rest of the pastry to form a lid and fit it over the filling, sealing well all round, trimming and pinching (or fluting) the edges. Make a small hole in the centre of the lid and, if you have time, you can use the trimmings to make a few leaves for decoration. Now brush the pie with the beaten egg, place it on the baking sheet in the oven, then after 10 minutes reduce the heat to gas mark 4, 350°F (180°C) and bake for a further 45 minutes. If the pastry gets a bit too brown during cooking, cover it with foil. Allow the pie to cool, then wrap it (plate as well) in a double thickness of foil ready to take on the picnic.