Place the flour and butter in a bowl and rub together into crumb consistency.
Add the sugar and the egg, and mix together. On a lightly floured surface, fold until the pastry until it just comes together.
Wrap the pastry in plastic wrap and chill for 30 minutes.
Mix Satsumas, zest and pie filling together Heat oven to 400°; have a small glass of wine. Roll out the pastry to 1/8 inch thick. Using a round cutter, cut out 16 (4-inch) bases and place them into (sprayed) muffin pans.
Put 1½ tablespoons mincemeat mixture into each. Brush the edge of each pie with a little beaten egg.
Re-roll out the pastry, cut out 16 (2½-inch) round lids and press them on top to seal. Glaze with the rest of the egg, sprinkle with sugar, then make a small slit in each pie lid. Bake mince pies for 15–20 minutes, until golden brown. Leave to cool before releasing them from the muffin trays and dusting with confectioners’ sugar.
Eat, drink and be merry!