Step 1

Heat the oven to 180°C/160°C fan/gas Lightly grease 2 sturdy non-stick baking trays with a little butter. Roughly chop the currants into smaller pieces.

Step 2

Sift the flour and salt into the bowl of a food processor or a mixing bowl. Add the butter pieces and pulse, or work together with your fingertips until the mixture looks like fine breadcrumbs. In a mixing bowl, stir in the caster sugar, then mix in the milk a few drops at a time until it comes together to form a firm dough. If the dough is quite warm, chill for 20 minutes.

Step 3

Knead the biscuit dough briefly on a lightly floured surface until smooth and pliable, then roll out to a large even rectangle 4mm thick. Cut the dough in half to form 2 rectangles.

Step 4

Sprinkle one of the rectangles evenly with the currants and lay the second rectangle on top. Sprinkle the work surface with a little more flour, then evenly roll out the layered dough into a large rectangle 4mm thick and about 24cm x 30cm.

Step 5

Trim the edges neatly, then cut the rectangle lengthways in half and then across into fingers about 3cm wide and 8cm long. Prick the dough all over with a fork, then brush with the egg white and sprinkle with granulated sugar.

Step 6

Using a palette knife or fish slice, carefully lift the biscuits onto the prepared baking trays, spacing them out evenly. Put the trays in the oven and bake for 12 minutes until lightly golden brown. Remove from the oven and leave to cool on the trays.