Preheat the oven to 180°C (350°F/Gas 4). Line two baking trays with baking paper.
Cream the butter, sugar and golden syrup in a small bowl with electric beaters until light and fluffy. Add the egg gradually, beating well after each addition. Transfer to a large bowl. Sift the dry ingredients onto the butter mixture and mix with a knife until just combined. Combine the dough with well-floured hands. Turn onto a floured surface and knead for 1–2 minutes, until smooth. Roll out the dough on a board, between two sheets of baking paper, to 5mm (¼inch) thick. Refrigerate on the board for 15 minutes to firm.
Cut the dough into shapes with a 13cm (5inch) gingerbread person cutter. Press the remaining dough together and re-roll. Cut out shapes and place the biscuits on the trays. Place currants as eyes. Bake for 10 minutes, or until lightly browned. Cool completely on the trays.
To make the icing, beat the egg white with electric beaters in a small, clean, dry bowl until foamy. Gradually add the lemon juice and icing sugar and beat until thick and creamy. Divide the icing among several bowls. Tint the mixture with food colourings and spoon into small paper piping (icing) bags. Seal the open ends, snip the tips off the bags and pipe on faces, bows and buttons.