Sift the flour into a bowl with a good pinch of fine salt. If you’d prefer to keep it nut-free, swap the ground almonds for the same amount of extra flour. Grate in the cold butter, then rub this into the flour with your fingertips until the mixture looks like damp sand.
Stir in the ground almonds (or extra flour) and sugar. Whisk the egg yolks with the orange blossom water, if using, and a tablespoon and a half of ice-cold water (two, if you’re not using the orange blossom water) – add just enough to bring the mix together into a firm, but not wet dough. Shape into a ball by hand, wrap well, and chill for half an hour.
Heat the oven to 200C (180C fan)/390F/gas 5. Grease two tartlet tins of whatever size you prefer with butter, and roll out half the pastry on a lightly floured surface until about 3mm thick. Cut out bases a little larger than the tin holes and use to line them, then fill each about three-quarters full with the mincemeat.
Roll out the other half of the pastry and cut out into rounds the same size as the tin holes. Alternatively, cut out stars or hearts, or top the pies with nuts (whole pecans and flaked almonds are nice) or even marzipan shapes, if you prefer less pastry-heavy pies.
If using a pastry top, dampen the edge of the lids with a little water or milk, and press down lightly on the pies to seal. Brush the tops with milk or beaten egg, sprinkle with sugar, and prick with a fork. Bake for about 20 minutes, until golden, then cool on a rack before serving.