In a large mixing bowl place sultanas, currents, raisins, mixed peel, cranberries and dark brown sugar. Finely Slice the apricots and prunes and add to the other ingredients.
Finely grate the orange zest and grate the apples coarsely and add the apple and zest to the other ingredients with vanilla, cinnamon and ginger.
Mix all ingredients together until well combined and pour over the sherry, mix well again and cover the bowl with cling film and leave in a cool place overnight to macerate or in the fridge for 3-4 weeks.
For the pastry mix together flour and caster sugar, add very cold, diced butter and rub the butter into the flour until it resembles coarse breadcrumbs.
Next add the duck fat and work it into the flour and butter briefly. Finally add a little cod water until the dough comes together.
If the dough is too sticky add a little extra flour.
Once the dough is smooth wrap it in cling-film and place it in the freezer to completely chill.
Lightly butter muffin tin/s and remove the pastry from the freezer. Work the pastry until pliable but still very cold. Roll the pastry out to approx .5cm and cut out enough pastry discs for tart bases and tops.
Line the muffin tins with the pastry and fill the pastry shells and place the pastry lids on top pressing down so the base and
top meets.
Briefly whisk an egg yolk and brush the top of the tars with egg yolk, sprinkle over caster sugar and leave the tarts on the bench to rest for 15 minutes. Once rested place the tarts in a pre-heated oven 170 °C combi mode and bake for 20-25 minutes until golden.
Once baked remove the tarts from the oven and rest in the tin for 5 minutes, cool the tarts on a wire rack and sift over icing sugar if desired.