Preheat oven to 200C/400F/Gas 6.
Rub the butter into the flour and add the almonds, caster sugar, orange rind and salt until the mixture is a bit crumbly.
Combine mixture with the egg yolk and 1-2 teaspoons of water until it forms soft dough, then put it into a plastic bag and chill for 20 – 30 minutes.
Roll out the pastry to a thickness of 2-3mm(0.1in) and cut out about 18 rounds measuring 7.5cm(3in) with a pastry cutter.
Place in lightly greased patty tins and spoon the mincemeat evenly into the pies.
Re-roll the leftover pastry and cut out round lids, stars or other festive shapes to fit on top of the mincemeat.
Lightly brush the pastry tops with the beaten egg and bake in the oven for 12 – 15 minutes until golden.
Remove from oven and leave for a few minutes before removing from tins and cooling on a wire rack.
Dust with icing sugar.