Scoop your mincemeat out of the jar and into a bowl, mix in your orange zest and then your whisky. Cover and set aside whilst you make your pastry,
Add your flour and sifted icing sugar to your food processor and pulse to mix together.
Dot over the cold, chunks of butter and pulse about 20 times, then stop and give the mixture a shake to ensure the dry flour from the base mixes in fully.
Keep pulsing until the mixture has a sand-like consistency.
Sprinkle over your lemon zest and pulse a few times to mix in.
Add your egg and pulse until it just starts to incorporate and then add your milk and pulse just until the mixture starts to clump together in lumps.
Lightly flour your work surface and then tip out your pastry mixture onto it.
Bring the pastry together into a ball, it should easily stick together when pressed. If it is crumbly and the ball of dough easily breaks apart, return it to your food processor and add another teaspoon of cold milk. If it is very sticky add a little more flour.
Flatten the pastry out into a circle about 1 inch deep and then wrap it in cling film and refrigerate for at least 30 minutes. This is very important as it sets the butter and ensures your pastry has a crumbly and flaking texture and it also prevents it from shrinking in the tin when baking.
Heat your oven to 200℃ Fan/Gas mark/400℉/Gas mark 6.
Grease your muffin tin cavities with some extra butter.
Roll your chilled pastry out to a depth of about 2-3 mm and then cut out circles using your 8cm cutter.
Drape a pastry circle over the top of a muffin cavity and then gently press it into the tin so that it touches the base. Don't worry about pushing right down into base, the pastry will flatten out when baking.
Add 2-3 teaspoons of mincemeat into each pastry case and level out. The mincemeat should come to just below the top of the pastry case.
Cut out small stars and place them on top.
Beat an egg and using your pastry brush, gently brush the egg wash over the pastry star.
Bake for 15 minutes or until the pastry is golden.
Leave to cool in the tin for at least 5 minutes and then, using a small spatula or a butter knife, gently push the mince pies out and leave to cool fully on your cooling rack.
When fully cooled, sift over some extra icing sugar or sprinkle over a little caster sugar.