Preheat oven to 190 degrees C and grease 3 baking trays.
In a large bowl combine the flour, sugar and baking powder. Cut in the butter until the mixture resembles coarse breadcrumbs.
In a separate bowl beat the eggs, milk, seeds and lemon zest until well blended. Add to the dry ingredients and blend until smooth. If the dough seems slightly stiff you can add extra milk, one tablespoon at a time.
On a floured surface, roll the dough to a half centimetre thickness. Cut biscuits using a 5cm round cutter. Place biscuits on greased baking trays, 5cm apart.
Bake in preheated oven for 7 to 10 minutes until edges are lightly browned. Cool on wire rack.