Prepare the
pastry : mix together the
flour,
salt and baking powder ; slowly incorporate the
margarine, the beaten
egg and then, little by little, the water. The dough should form a ball and it should not get sticky. Always
work on a little extra
flour and stop adding water if the dough gets sticky. Put the dough in a bowl, cover it with a clean sheet and keep in fridge till the day after.