Mix the flour, baking powder and sugar.
Grate the butter into the dry mixture.
Rub the butter into the flour to form breadcrumbs.
Slowly add the egg/milk mixture and the blueberries. Gently stir the liquid into the dry ingredients to form a sticky dough ( you may not need all the liquid)
Tip onto a floured surface and form a circle shape.
Cut in half and layer on top.
Repeat this process
Cut into triangles, optional- brush with egg and sprinkle with sugar.
Bake in a preheated oven at 220 degrees C for 12-15 minutes.
