Mix flour, salt, sugar. Cut the butter into cubes and rub it into the flour mix - crumble the
butter between your finger tips, and don’t work it too much.
Dissolve the starter in the water, then add to the rest of the ingredients: only mix until
everything comes together, don’t knead or you’ll lose some of the flakiness.
Make a ball, and wrap it with cling film, then place it in the fridge for 30 minutes or overnight.
Take the dough out of the fridge, let it soften a little if it’s hard (it won’t be after 30 mins, but
the longer it sits in the fridge the harder it gets).
Roll it out into a rectangle or a circle, place the filling on it, leaving a 3-4cm border. Fold the
border over the filling, and brush with egg wash (optional).
Bake for about 20-30mins at 180C/350F - baking time will also depend on the filling you use.