To make the mincemeat, place the currants, raisins, sultanas, dried cranberries, candied mixed peel, margarine, brown sugar, almonds, grated bramley apple, spices and orange zest and juice into a large pan. Heat gently, stirring, until the margarine has melted then simmer very gently, stirring occasionally, for about 10 minutes.
Remove from the heat and leave to cool until just warm then stir in the alcohol of your choice. Cover and refrigerate until needed. You can also decant it into sterilised jars, seal and store for up to six months.
For the pastry, put the flour, icing sugar, salt and margarine into a food processor, whiz for a minute or so until the mix resembles breadcrumbs.
Add a little cold water, whiz again briefly until the pastry comes together; adding a few more drops of cold water if necessary.
Tip the pastry onto a lightly floured surface and bring it together with your hands to form a ball, then flatten into a disc. Wrap in clingfilm and chill it for 30 minutes.
For the shortbread stars, use a hand mixer to mix the margarine and sugar together until pale and creamy. Tip in the flour, salt and cinnamon and mix again to combine, if it seems too dry then you can add a drop of milk to help bring it together. Shape the dough into a disc as you did with the pastry, wrap it in clingfilm and chill it for 20 minutes.
Roll out the pastry on a lightly floured surface until it slightly larger than a 20x30cm/8x12 inch rectangular tart tin, then press into the tin to line it; leaving the excess pastry overhanging. Pop in the freezer for 20 minutes.
Preheat the oven to 200°C/400°F/gas mark 6. Place a baking tray in the oven to heat up. Line the pastry case with tin foil and fill with ceramic baking beans or dried rice. Place the tart on the preheated baking tray and bake for 20 minutes.
Remove the foil and baking beans and return the tart to the oven for 10 minutes until pale golden. Keep an eye on the edges and cover them with tin foil if they start to get too dark. Set aside to cool slightly.
While the tart case is blind baking, roll out the cinnamon shortbread on a lightly floured surface to about 6mm/¼ inch thick. Use a variety of star shaped cutters (smaller is better) to cut out lots of star shapes. Re-roll the scraps and cut out more stars.
Place the stars on a couple of baking trays and put them in the freezer for 20 minutes.
Fill the baked tart case with the mincemeat (you wont need all of it). Arrange some of the stars on top. Brush with a little dairy free milk and sprinkle with granulated sugar.
Bake for about 30 minutes, until the stars are golden. If the edges of the tart start to brown too much then cover them with strips of tin foil. Set aside to cool in the tin before carefully unmoulding and serving.
Place the remaining stars on a baking sheet, slightly spaced apart. Brush with milk and sprinkle with sugar as before then bake for about 10 minutes until golden. Cool on a wire rack and store in an airtight container.