To begin, place the flour, salt, and diced butter into a large mixing bowl. Rub the butter into the flour with your fingertips until the mixture resembles fine breadcrumbs. Add the caster sugar, then stir in the egg yolk and just enough cold water to bring the dough together. Gently form into a ball, wrap in cling film, and chill for 20 minutes before rolling. This resting period prevents the pastry from shrinking during baking.
In a large bowl, combine the dried fruits, mixed peel, chopped almonds, grated apple, brown sugar, and suet. Add the citrus zest and juice, spices, and brandy or rum if using. Stir thoroughly to coat the fruit evenly. Cover and leave to sit for at least 30 minutes to let the flavours meld.
Set your oven to 200°C (fan 180°C) or Gas Mark 6. Lightly grease a 12-hole muffin or tart tin with butter or non-stick spray. While the oven heats, remove the pastry from the fridge to soften slightly for rolling.
On a lightly floured surface, roll the pastry to about 3mm thick. Cut out 12 circles using a round cutter (about 8–9cm wide) to line the tin holes, gently pressing each circle in place. Reserve the remaining pastry for the lids.
Spoon a heaped teaspoon of the prepared mincemeat into each pastry case. Avoid overfilling to prevent leakage during baking.
Re-roll the remaining pastry and cut out slightly smaller circles (or use star shaped cutters for a festive look). Place these on top of the filling, gently pressing the edges to seal. Brush lightly with beaten egg for a golden finish.
Place the tin in the preheated oven and bake for 18–20 minutes or until the pastry is crisp and golden brown. Rotate the tin halfway through baking for even colouring.
Allow the mince pies to cool in the tin for 5 minutes before transferring them to a wire rack. Dust generously with icing sugar once completely cool.
Serve warm or at room temperature with a dollop of brandy butter, clotted cream, or custard. These mince pies pair perfectly with tea or mulled wine, embodying the spirit of a traditional British festive table.