Sift thhe flour into a large bowl and rub in the butter with your fingers until the mixture resembles bread crumbs.
Add the salt and 3-4 tablespoons of cold water and mix into a soft dough.
Knead the dough together and form a ball. Wrap in cling film and place in the fridge whilst you make your Black Bun filling.
For the Filling
Pre-heat your oven to 160°c. Grease and line a 7 inch round cake tin or a 2lb loaf tin with grease-proof paper.
Mix all the filling ingredients in a large bowl - is should be of a sticky consistency. Set aside.
On a lightly floured surface, roll out 2/3 of the pastry thinly. Drape into your pre-lined tin and press up against the sides.
Spoon in the filling to the pastry-lined tin and push down with the back of a spoon.
Roll out the remaining pastry to the same thickness as before, large enough to cover the top of your tin. Brush the edges of the pastry with a little water and press on top of your black bun to seal. Trim the edges and crimp with a fork to finish.
Glaze with a beaten egg, prick some holes in the top of the pastry and bake for 2 hours. If you feel your black bun is looking a little brown on top, cover with a sheet of tin foil half way through the bake time.
Remove from the oven and allow to cool completely in tin before turning out to cut and serve.
For the filling, its personal preference which dried fruit you use. I tend to opt for whatever we have in - usually a combination of all currants, raisins & sultanas with amounts determined on how much I have to hand.