Panino con stigghiola is Palermo street fire put inside bread, and the defining element is the grill, not the bread. Stigghiola is lamb or kid intestine, cleaned and then wound tightly in a long spiral around a stalk of spring onion or a skewer, salted, and cooked directly over fierce charcoal until the casing blisters, chars at the edges, and renders down to something chewy and smoke-bitten. It is a stigghiularu's open-air craft, the meat turned over coals on the kerb and the air thick with its smoke, and the panino is simply the way you carry it off without a plate. The whole sandwich is that charred, gamey, onion-scented offal; the roll is a carrier and a heat shield, nothing more.
The craft is in the wind and the fire. The intestine has to be wound evenly and tight so it cooks through to tender while the outside crisps, and the charcoal kept hot enough to char fast rather than stew the casing slowly, which would turn it rubbery and rank. The onion at the core steams inside the spiral and sweetens against the smoke. It comes off the grill seasoned with little more than salt, a hard squeeze of lemon, and sometimes a dusting of pepper, then is cut and packed straight into a plain, soft Palermo roll, often a sesame one, while it is still spitting hot. The bread is deliberately neutral and slightly absorbent so it takes the rendered fat and the char without arguing; eaten the moment it is handed over, before the casing cools and stiffens.
The variations stay on the same Palermo street. Stigghiola shares its corner and its fryer-and-grill grammar with the city's other offal cooking: spleen packed into a roll, quarume of simmered tripe, the boiled-meat stalls, each cooked hard and eaten standing. They are different cuts handled by different methods, hot and bought from a stall and not built at a counter. Each deserves its own article rather than being crowded in here.