In a bowl of milk soak the bread into pieces, drain it and add it into the electric mixer with the slices of Mortadella together, olives, parsley, a whole egg and Parmigiano Reggiano. Mix everything. From the dough, form round-shaped meatballs. In a separate dish put the breadcrumbs and roll the mortadella meatballs. Then place the meatballs on a baking tray lined with baking paper, on which you have previously poured seed oil. Bake for 25 minutes at 180 degrees.