The puccia salentina is defined by its bread before anything goes inside it. The puccia is the soft Salentine round, a flattish disc of plain wheat dough from the heel of Puglia, baked tender with a thin pale crust and an open, slightly chewy crumb that carries almost no seasoning of its own. As a sandwich it is split through the equator into a wide pocket and that pocket is the build: a quiet, absorbent shell waiting for a filling to define it. The defining fact is structural rather than a single ingredient. The puccia gives nothing loud and asks nothing back, which is exactly why it works as a base, it takes oil, salt, and fat from whatever it holds and turns a handful of components into one contained bite. Without a filling it is a plain roll; without the soft pocket the filling has nowhere to sit. The two halves of the proposition are matched so a neutral bread can frame an assertive load.
Making it well begins with the dough and the pocket. The puccia is best baked the same day and used soft, the crumb still yielding, because a stale tight round shatters at the crust and the fill spills rather than settling. It is split with a wide opening so the chamber holds its contents flat instead of bulging them out one side, and the inner crumb is left intact so it can soak the oil and rendered fat that bind the bite together. The filling is folded in loosely rather than packed dense, so the bread can close and the fat spreads thin across every mouthful instead of pooling. Seasoning comes from what goes in, a thread of good oil where the crumb runs dry, salt from a cured element or from the dough itself, never a heavy sauce that would drown the bread's gentle character. A sloppy build uses a hard day-old round and a tight overstuffed core that reads as one greasy mass; a good one is soft, generously but loosely filled, and balanced so the plain bread and its load add up.
The close cousins all sit inside the same puccia family and each is its own subject rather than a footnote here. There is the puccia con capocollo built on spiced cured pork neck, the puccia con carne di cavallo on horse meat, the all-vegetable puccia con verdure, and the uliata with black olives worked into the dough under the same fillings. Each is the same soft-round-bread-meets-filling idea with one element changed, and each deserves its own article rather than being crowded in here.