Mortadella may be new to you. It was to me. A lightly smoked Italian sausage -- usually ham, though there are pork and beef versions as well -- it's studded with pistachios and seasoned with parsley, basil and cilantro. (Traditionalists add myrtle -- mortella, in Italian -- which explains the name.) Segafredo Zanetti (1909 West Gray, 807-7135) makes a terrific mortadella sandwich ($5.50). Consisting of panini, mortadella imported from Bologna and fresh mozzarella, the sandwich is grilled in (what else?) a panini machine -- a contraption, I'm told, that looks a lot like a waffle iron. It makes for a memorable snack. One bite and you'll imagine yourself on Rome's Via Veneto.