-
Lightly grease 2
baking trays.
-
In a large mixing bowl, cream together
the butter and sugar and until pale and fluffy.
-
Add
the lemon zest and juice, then the egg yolk and beat
until they are thoroughly combined. Stir in the
rosemary.
-
Add
the flour, mixing well until a soft dough is formed.
Wrap and leave to chill for 30 minutes.
-
Preheat the oven to 180°C/350°F/Gas mark 4.
-
On a lightly floured
surface, roll out the dough thinly and then stamp
out 25 circles with a 6cm/2 1/2in biscuit cutter. Arrange the dough circles on
the prepared baking trays.
-
In a bowl, lightly whisk
the egg white. Gently brush the egg white over the
surface of each biscuit.
-
Bake in the oven for about
15 minutes. Transfer the biscuits to a wire rack and
leave to cool before serving.