Preheat the oven to 160c. Roll out the pastry to 5mm thick. Using a pastry cutter, cut 12 larger rounds (slightly bigger than your tartlet or bun tray moulds) and 12 smaller rounds (using a cutter one or two sizes smaller). Lightly grease tartlet trays.
Line the tart or bun trays with the larger pastry rounds, pressing them gently into place. Fill each with mincemeat, levelling it with the edges of the pastry.
Lightly brush the edges of the smaller pastry rounds with beaten egg, then place them on top of the filled tarts. Seal by gently pressing the edges together. Cut a small hole or prick the tops with a fork to allow any steam to escape.
Brush the tops with more beaten egg and bake in the preheated oven for 25 - 35 minutes, or until golden brown.
Carefully remove the pies from the trays and transfer them to a wire rack to cool. Sprinkle generously with icing sugar before serving *Opt.