Preheat oven to 350 degrees. In a bowl, mix together the mincemeat with the nuts, cinnamon and maple syrup. Lay the pastry out so that one of the longest edges is facing you. Smooth two thirds of the mincemeat mixture over the pastry to cover it entirely
Take the two shorter edges of the pastry and fold them over to meet in the middle.
Spread again with the remaining mixture, then repeat the folding same as above.
Place the pastry on a tray and freeze for 10 minutes. Remove from the freezer and cut the pastry into 1/2" slices, placing flat down on the baking tray. Cook for around 15 minutes until the pastry is golden brown.