Sift the flour, baking powder and salt into a medium
bowl. Stir into a medium bowl. Stir in the sugar.
Use a pastry blender to cut in the shortening until
the mixture resembles fine crumbs. Stir in the
currants.
Mix in enough water to form a stiff dough. Press the
dough into a disk, wrap in plastic wrap, and
refrigerate for 30 minutes.
Preheat the oven to 400°F/200°C/gas 6. Butter a cookie
sheet. Roll out the dough on a lightly floured
surface to a thickness of 1/4 inch (5mm).
Use a sharp knife to cut the dough into 2 inch (5
cm) squares. Gather the dough scraps, re-roll, and
continue cutting out cookies until all the dough is
used.
Use a spatula to transfer the cookies to the
prepared cookie sheet, placing them 1 inch (2.5cm)
apart.
Bake for 8-10 minutes, or until golden. Transfer to
racks to cool.