Sift the flour and icing sugar together and tip it into the food processor.
Cut the butter up into little cubes and add to the flour.
Pulse the food processor until you get a grainy mix that resembles breadcrumbs with some tiny, butter bits.
Add 1 Tbsp of the ice cold water and pulse again. Stop when the mixture comes together to form a dough. Pick a little bit up and pinch between your fingers. If it sticks together like dough, it's done.
If not, add 1 Tbsp more of water and pulse and check again. Use another Tbsp of water if necessary. Don't add too much water as your pastry will be hard.
When done, tip out onto your work surface and bring it all together to form a dough. Press your mix together, kneading it for 30 seconds to form a smooth dough. Overworking your pastry will make it tough.
Wrap in cling film and rest in the fridge for 30 minutes.If your pastry has stayed in the fridge for over 1 hour, let it rest for 10 minutes before rolling it, otherwise it'll be too hard and will crack.If left overnight, let it rest for 30 minutes at room temperature.
Pastry – by Hand
Sift the flour and icing sugar into a large bowl.
Cut the butter up in cubes and add to the flour.
Rub together with your fingertips, lifting the flour up and letting it fall back. This "airing" helps to keep your pastry light.
When the mixture begins to resemble breadcrumbs, with the odd lump here and there, sprinkle 1 Tbsp of cold water all over.
Mix it up with your fingertips until it begins to come together. Add more water if needed, 1 Tbsp at a time.
Tip it out onto your work surface and knead as mentioned above, to get a smooth dough. Wrap in clingfilm and chill for 30 minutes.
Making the Mince Pies
Preheat the oven to 200℃/400℉ 180 ℃ Fan.
Roll out the pastry on a lightly floured surface to a thickness of 3mm (0.1 inch).
Use an 8 cm (3 inches) fluted cutter to cut circles and gently press them into the tray. Fill each mince pie case with 1 heaped teaspoon of mincemeat.
Using festive shaped cutters, cut out tops for your mince pies. Place the shapes on top of the mincemeat and brush the pastry with the milk or beaten egg.You could also cover them completely. Brush the edge of each pie with a little milk or beaten egg. Then cut 7cm (2.75 in) lids and press them on top to seal the mince pies. Brush the lids with milk or beaten egg. Make a small cut with a pair of scissors on each lid to allow steam to escape. Or just poke through with a fork.
Sprinkle a little caster sugar all over, just lightly.Bake in the preheated oven for 15 - 18 minutes, until a light golden brown. You may even need 20 minutes, as all ovens differ.
Cool completely before getting them out of the muffin tray. Dust with icing sugar before serving. They are great as they are, but many also enjoy them with custard or cream. Store in an airtight container for up to 4 days.
Notes
How many mince pies you get will depend on the size of your muffin tray and cutters, as well as how thinly you roll the pastry. I use a 9 cm (just over 3.5 in) cutter for the base and only get 12 mince pies. This will also affect the amount of mincemeat you need. I use 600 g (about 1.3 lb) for the 12 mince pies.