Place the butter-flour on a well floured surface. In its center place the simple dough. Fold the butter-flour all around the simple dough, to trap it completely.
Roll out the dough with a pastry roll, lengthwise.
Make a single fold, turn a quarter turn (to have the opening facing you), spread out again lengthwise and then make a double fold.
Wrap the dough and place in the refrigerator for at least 1 hour.
Place the dough on a floured surface.
Spread the dough lengthwise, make a single fold, turn a quarter turn, spread again and make a double fold. Wrap and place in the refrigerator.
After at least 1 hour in the refrigerator, the dough is ready to use.