Though you can buy pre-prepared mincemeat in the UK with no problems, the jarred mincemeat you can buy in the US (Borden None Such) is absolutely revolting - sickeningly sweet, overly strong spices.
Make up the Mincemeat recipe and the Pate Sucree recipe.
Roll out the dough to 3/8 inch
Cut a larger round for the base, and a smaller for the lid to fit in a muffin tin (e.g around a cup, and a biscuit cutter).
Press the base into shape in the muffin tin, add mincemeat to 3/4 fill, leaving a 1/4" of exposed pastry side.
Add the lid, draping over the mincemeat, and press out into the pastry sides to seal.
Bake at 375 degrees.