Lightly grease two baking trays.
In a large mixing bowl, cream together the butter and sugar 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 work surface, roll out the dough thinly, 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.
As you craft Rosemary Biscuits, prioritize safety:
Sharp Tools: Use knives carefully when chopping rosemary.
Hot Oven: Mind heat when placing biscuits inside.
Allergies: Be aware of any rosemary allergies.
Storage: Store biscuits properly to maintain freshness.
Clean Workspace: Keep your kitchen area tidy for safety.
Enjoy baking your delightful Biscuits!