Pour the flour on the pastry board forming a cone with a cavity on the top (a fontana in Italian, i.e. "like a fountain"). Add the strutto and knead the dough using just enough lukewarm salted water (not hot) so as to obtain a rather firm dough. Knead vigorously for 10 mins. and divide the dough into pieces to be rolled out or stretched by hand to make each piadina about 8 in. in diameter.
Heat up the testo on burning coal, or on a stove, and lay on a disk of dough (do not brush with oil). Let cook well on one side and then turn it over; when you notice little charred bubbles forming on the disk, the dough is ready. Continue cooking several disks of piadina in this way, placing the ones that are ready in a pile so that they keep warm.
Serve piadina either plain instead of bread or folded over with a filling such as: cheese, mortadella, prosciutto, or a cooked green vegetable, such as chicory or bitter broccoli.
Note:
Piadina can also be cooked into an 8-in. round cast iron pan.
