Roll the pastry dough into a 10-in/25-cm square. Brush one-half of the pastry with the tomato paste. Lay the prosciutto over the tomato paste, then dust with some of the cheese.
Fold the 2 outer quarters of the dough toward each other to meet in the middle, leaving a ½-in/1-cm gap. Sprinkle the remaining cheese on top of the length of the dough. Complete the