Combine the flour, sugar and salt in a medium sized bowl or in the bowl of a food processor. Using either a pastry blender or the food processor, cut in the butter until only a few pea sized pieces remain.
Add the egg and pulse in the food processor until combined, or use a spoon.
Slowly add the water, 1 tablespoon at a time until the dough just starts to come together in a ball. Take the dough out of the bowl and using your hands on a lightly floured surface, form it into a smooth ball. Flatten the dough into 2 discs, wrap in gladwrap and place in the fridge for at least 30 minutes until needed. At this point you may want to freeze 1 of the discs - place in a snaplock bag and freeze.
Once the dough has chilled, roll out to a thickness of about 4-5mm. Using a round cookie cutter, cut out circles the size of the tins you will be using and place in the tins. I like to use mini muffin tins, but regular muffin tins would work too.
Fill each pastry case with a generous spoonful of Christmas fruit mince. You can leave them as is, or make pastry cut-outs to sit on top.
Bake at 180°C for 20-25 minutes, until the pastry is golden brown.
Allow to cool for a few minutes in the tins before transferring to a cooling rack.
Dust with icing sugar before serving.
Store in an airtight container at room temperature for 1 week.