In a Robo, pulse the flour, bitter and salt together until fine ‘breadcrumbs’. Pour into a large bowl and make a well.
Add the water and slow incorporate without overworking the pastry.
Push into a ball, cover and let rest in the fridge for at least 30 minutes.
Roll out the pastry to 2-3mm and line a buttered pie tin.
Add the filling and top with a pastry lid, then crimp the edges closed.
Egg wash and pierce a small hole in the top to allow the steam to escape.
Bake in the oven at about 160c for 25-30 minutes until golden.
If they are to be eaten later, chill and reheat in the oven for 15- 20 minutes on 180c.