Preheat oven to 275°F.
Mix all the mincemeat ingredients together in a large bowl then transfer the mincemeat to a casserole dish. Transfer to the oven and cook for 2 hours. Once cooked, leave to cool then transfer to sterile jars. You’ll need 9 ounces for the pie.
For the pastry: place the flour, salt and butter in a food processor and whiz. Add half the beaten egg and continue to blend. You might add a little more egg, but not too much as the mixture should be just moist enough to come together.
Using your hands, transfer the pastry from the food processor out onto a work surface and flatten out the ball of dough until it is about an inch thick. Wrap in cling film or place in a plastic bag and leave in the fridge for at least 30 minutes to chill.
Once the pastry has chilled, preheat the oven to 400°F. Brush a shallow 24-hole cupcake baking tin with melted butter and set aside.
On a floured work surface, roll out the pastry to 1/4-inch thick and, using a large (around 5 1/2 inches), round, cookie cutter, cut out 12 circles for the bases. Then use a smaller star cutter to cut out 12 circles/stars for the lids.
Line the holes of the buttered cupcake baking tin with the pastry bases. Fill each base with a teaspoon of mincemeat and top with a pastry star. Brush the tops of the mince pies with the beaten egg.
Place in the pre-heated oven for 15-20 minutes, until golden on top and browned around the edges. Let cool slightly, the dust with sugar.