Add all of the ingredients, except the booze, to a big bowl and, taking advice from the tremendous Delia Smith, leave to mingle for at least 12 hours. Cover and leave in a cool spot. It will smell SO MUCH like Christmas. Don't worry if you don't have time.
Then tip the ingredients into a big saucepan and warm over a medium heat. Stir. Lots.
Once the sugar and the suet have begun to melt, reduce to heat to extremely low and cover. Leave for around 2 hours but do keep an eye on it so it doesn't catch and stir occasionally. Alternatively, pop into an oven-proof covered dish and leave in the oven at around 110-120 degrees for up to 3 hours.
Remove from the heat and leave to cool.
Once cool, chuck in the booze and stir through thoroughly.
Spoon into your sterilised jars, seal with lids and store, or use straight away.
To make the pies, cut a strip of filo and fold to make a pocket, as per the pictures.
Spoon in a dollop of chestnut purée or marzipan, a dollop of mincemeat and then fold over the remaining flap to make a triangular samosa shape. Use skimmed milk to seal it.
Glaze with more skimmed milk and bake at 180 degrees fan for around 12-15 minutes.