Ingredients

Step by step

1. Using an electric hand whisk, whisk together the butter and caster sugar until light and creamy. Beat in the egg yolk, lemon zest and 1½ tbsp of the juice. Stir through the flour and almonds, then bring together with your hands.
2. Turn out onto a work surface lightly dusted with flour, and knead briefly. Cover the dough with clingfilm and chill in the fridge for 10 minutes. Preheat the oven to 180ºC, fan160ºC, gas 4.
3. Place the dough onto a large piece of baking paper and roll out to large circle, approximately 5mm thick, using a rolling pin dusted with flour. Keep turning the baking paper as you roll, rather than the dough, to help create a circular shape. Use a 23cm dinner plate or cake tin as a template and cut round the circle.
4. Slide the circle of dough onto a baking sheet, keeping the baking paper underneath. Using a sharp knife, score the circle into 8 segments (but don't cut through); chill for a further 10 minutes, then transfer to the preheated oven and bake for 13-15 minutes, until deep golden. The biscuit will still be soft to the touch, but will firm up on cooling.
5. Remove the cooked biscuit from the oven and re-score the segment lines while the biscuit is still warm. Cool on the baking sheet for 10 minutes then slide onto a wire rack to cool completely.
6. To decorate, place the icing sugar in a bowl with the egg white, remaining lemon juice and 1½ tbsp water. Whisk to combine.
7. Put 175g of the icing into a separate bowl and mix in the yellow food colouring, a little at a time, until you have a vibrant yellow colour. Spoon into a disposable piping bag fitted with a small round nozzle.
8. Pipe a yellow outline around the edge of the entire biscuit, allowing the icing to break at each of the 'segment' joins. Squeeze the remaining icing back into the bowl and set aside.
9. Rinse and dry the nozzle and fit into a clean piping bag, fill with the white icing and pipe a triangle within each 'segment' (inside the yellow outline). Create a 1cm border along the 'base' of the triangle by piping a second white line 1cm from the first white line. Pour the remaining icing back into the bowl. Thin the icing a little with a few drops of water, then use a little of the white icing to fill the 1cm border. Use a teaspoon and a cocktail stick to help nudge the icing into the corners. Cover and reserve the leftover icing.
10. Add a few drops of water to the yellow icing and use the same 'flooding' technique to fill the triangle above the border with yellow icing. Allow to set.
11. Stir the reserved white icing to loosen and using a teaspoon, gently flick white icing over the yellow to create 'highlights'. Allow to set before serving.
12. Watch this...

    Icing lemon biscuits