1. To make the pastry, put the flour in a food processor, add the butter and lard and blend until the mixture resembles breadcrumbs. Add the icing sugar and blend lightly to mix. Add enough cold water, about 4-5 tbsp, to mix to a firm, smooth dough. (Alternatively, rub the fats into the flour in a bowl then add the sugar and water to mix to a dough.) Turn out onto a lightly floured surface and knead into a smooth ball. Wrap in clingfilm and chill for at least 1 hour.
2. To make the filling, turn the mincemeat out into a bowl and add the cranberries. Peel the apple and grate the flesh into the bowl, working around the core. Add the sugar and spice and mix well.
3. Preheat the oven to 190ºC, gas mark 5. Thinly roll out three-quarters of the pastry on a floured surface and cut out rounds using a 8-9cm cutter. Use to line each hollow of 2 12-hole tartlet trays. Brush the edges with a little water and pile the filling into the centres.
4. Roll out the remaining pastry with the trimmings and cut out lids using a 6cm cutter. Position on the pies, pressing firmly together around the edges to seal. Brush with beaten egg to glaze.
5. Bake for 25 minutes until golden. (You might need to rotate the tins halfway through cooking.) Leave in the trays for 5 minutes then transfer to a wire rack to cool. Store in an airtight container for serving cold or until ready to warm through. Serve sprinkled with sugar.