For the filling, roughly chop the pork and put it into a food processor. Pulse briefly until it looks like coarse minced meat. (Be careful not to over-process or it will become too smooth — you want to have a bit of texture.) Or you can chop it very finely with a sharp knife.
Transfer the pork to a bowl. Finely chop the streaky bacon, leaving the fat on to keep the filling moist. Add to the bowl along with the onion, sage, parsley, nutmeg, pepper and a little salt. Cover and chill until ready to use. It is good to have the filling all ready to go, as you want to deal with the pastry quickly once it is ready to roll out.
Now make the pastry. Put the flour and salt into a large heatproof bowl. Tip the lard and butter into a small pan and pour in 150ml (¼ pint) water. Put this over a medium heat so the fats can melt, then raise the heat. As soon as it all comes to a boil, pour it into the flour. (Don’t let it simmer away or you will lose some volume.) Stir well with a wooden spoon until it forms a soft dough. Leave it for a minute or two so the dough is a bit cooler to handle.
Tip the dough onto a lightly floured surface and knead briefly until smooth. Wrap it in clingfilm and chill for 30-40 minutes. Try not to leave it much longer as this type of pastry can easily harden over time and become difficult to handle. It just wants to have cooled down a bit so it is easier to roll out.
Lightly butter six small pudding moulds. Preheat your oven to 400 degrees F. Divide the meat filling into six equal amounts. Cut the dough in half and keep one half wrapped while you shape the other half into a disc and roll out on a well-floured surface, to about ⅛ in thick. Using an upturned bowl or saucer as a cutting guide, cut out three 5½” circles for the base of each pie and three 3¼” circles for the lids. Re-roll any pastry trimmings if needed so you can cut out all three lids.
Line three of the small pudding moulds with the larger circles, pressing the pastry up the sides with your fingers so that it evenly covers the inside of the moulds, smoothing out any thicker folds that have formed. It should reach just above the top of each pudding mould.
Spoon a portion of the filling into each pastry-lined mould and press it down so that it is well packed in. It should sit slightly below the top.
Brush the pastry edges with egg and cover with the pastry lids, pressing them down on to the filling. Press the edges well together to seal, then flute them to decorate.
Brush the pastry with egg to glaze and make a hole in the middle of each lid with a skewer, to create a vent. Repeat with the remaining half of the pastry and filling so you have six pies.
Sit the pies on a baking sheet and bake for 40-45 minutes until the pastry is a rich golden brown. Remove them from the oven and let them sit for about 30 minutes. While they’re still warm, and in case any juices have bubbled over and stuck to the insides of the tins, loosen all round the edges of the pastry to make sure they can be released easily later. Leave the pies in their moulds for a couple more hours until completely cold and the juices have all gone back into the meat before turning them out.