Pork in Balsamic Vinegar / Maiale con Aceto Balsamico Umbria, the central region of Italy, is noted for its porchetta, or suckling pig, grilled on an open spit with fresh rosemary until the skin crackles and is almost bronze-colored. When I was studying the food of Umbria, I was inspired by the many ways pork is prepared, including this dish, which uses pork tenderloin. It is so easy to prepare and it can be cooked up to 3 days ahead. The marinade, which includes balsamic vinegar, gives the pork a flavor that is hard to beat.