The defining tension here is temperature and density: a hard, slow loaf against a cool, barely-set cheese. Pane di Altamura is a protected Pugliese bread of remilled durum wheat, dark-crusted, deep yellow in the crumb, dense and faintly nutty in a way that ordinary white bread is not. Burrata is its opposite in every register: a thin pouch of mozzarella enclosing stracciatella, shreds of curd loosened with cream until the inside runs when it is cut. Set one against the other and the sandwich is a single decision about contrast, the chew and the salt of the durum loaf carrying a filling that has almost no structure of its own.
The craft is in respecting how little the burrata can take. The loaf is cut thick, often torn rather than sliced, because its crumb has the spine to hold a wet, collapsing cheese without going to paste; a soft roll would have surrendered on contact. The burrata is left whole or split at the table and used at cool room temperature, never fridge-cold, when the stracciatella reads loosest and the cream has not stiffened. The dressing is minimal by necessity: a hard pour of olive oil, coarse salt, sometimes a turn of pepper or a torn basil leaf, because the cheese is mild and the bread is assertive and a third loud voice would only argue with the durum. It is assembled and eaten quickly, since the longer the cream sits against the crumb the more the bottom slice gives way.
The variations stay in the Puglian larder and the same logic of one dense bread under one soft thing: the loaf with stracciatella alone rather than the whole pouch, the version with a few sun-dried or ripe tomatoes worked against the cream, the burrata met with prosciutto crudo so a cured meat does the counter-work. Each is the same durum-and-cool-cheese idea adjusted by a single addition, and each deserves its own article rather than being crowded in here.