The panino con canestrato pugliese is built around a hard sheep cheese that carries the imprint of the basket it was pressed in. Canestrato Pugliese is made from the milk of grazing ewes, drained and shaped in a woven reed canestro that leaves a ridged basketwork pattern on the rind, then aged until it is firm, dry, and granular. What defines the sandwich is the cheese at the right age: young enough to still crumble cleanly rather than shatter to powder, sharp and faintly piquant from the long cure, salty in the way a grazing-flock cheese is. The bread is there to carry one wedge of it and nothing more, which is the whole Puglian instinct with a protected cheese.
The craft is matching how the cheese breaks to how it is laid in. Canestrato at a mid age is cut into thick irregular shards rather than thin slices, because a hard sheep cheese sliced fine on a roll just slips out, while a broken chunk holds its place and gives the bite some structure. It is paired with the dense, deep-crumbed durum-wheat bread of the region, often pane di Altamura, whose own toasted-wheat depth stands up to a strong cheese instead of disappearing under it. The only additions are the ones that answer the cheese's salt and dryness: a thread of local olive oil to carry it, sometimes a few drops of vincotto or a smear of fig or honey against the piquancy, occasionally fresh fava beans in spring when the flavour combination is at its sharpest. Nothing wet goes in, because moisture turns a granular aged cheese pasty and dulls the very edge that makes it worth eating.
The variations are mostly a question of age and what is allowed alongside it: the very aged canestrato grated coarse rather than chunked, the spring pairing with raw fava, the oil-and-vincotto build that leans sweet against the salt. Other basket-pressed and aged southern sheep cheeses, the pecorino forms and the cacioricotta among them, follow their own logic on their own breads. Each is one wheel given a loaf, and each deserves its own article rather than being crowded in here.