The sciatt in panino takes an Alpine fried cheese fritter and gives it a bread to live in, and the two depend on each other in a specific way. Sciatt are the buckwheat dumplings of the Valtellina: a loose batter of buckwheat and a little wheat flour, often slackened with grappa, wrapped around a nugget of Valtellina Casera or a similar mountain cheese and deep-fried so the outside sets into a dark, nubbly, faintly bitter shell while the centre turns to molten cheese. Tucked into a roll, the defining fact is the contrast the bread is there to manage: a craggy fried buckwheat crust and a hot liquid core, carried in a plain crumb that absorbs the frying fat and braces the soft middle so the whole thing can be held and bitten. Without the sciatt the panino is an empty roll; without the bread the fritters are eaten straight off the pan with nothing to contain the molten cheese. The two are matched so a rough fried dumpling becomes a contained bite.
The craft is in the fry, the cheese, and the timing. The batter is kept loose so it fries into an irregular, lacy crust rather than a smooth heavy ball, and the buckwheat is what gives that crust its dark colour and its slightly bitter, earthy edge against the rich cheese. The cheese core must be a melting mountain type cut in a generous nugget so it goes fully molten without leaking out before the shell sets, and the sciatt are drained well so the panino takes the right amount of fat and no more. The roll is plain and absorbent on purpose, split and filled while the fritters are still hot, because the appeal is the live contrast of crisp shell and flowing centre, and a sciatt gone cold and rubbery loses the point. Nothing heavy is added, perhaps only the faint sharpness the buckwheat already carries; a sauce would smother the fried crust the build exists for. A sloppy version uses a tight batter, weak cheese, and cold fritters that read as one greasy lump; a good one is craggy, molten, and freshly fried in a quiet roll.
The close cousins stay in the Valtellina fried and cheese register, each its own subject rather than a footnote here. There is the version finished over bitter chicory the way sciatt are often served on the plate, the relative built on pizzoccheri logic with buckwheat and the same Casera, and the broader Alpine fried-cheese-in-bread idea such as frico tucked into a roll. Each is the same fried-buckwheat-and-melting-cheese idea with one element changed, and each deserves its own article rather than being crowded in here.