The tramezzino ai carciofi is the soft Italian tea sandwich built around artichokes, and three things define it as a tramezzino before the filling is even chosen. It is made on pane in cassetta, the pillowy crustless white sandwich loaf, the crusts trimmed clean so only tender crumb remains. It is overfilled so the middle domes and the two triangles bulge rather than lying flat. And it is bound with a mayonnaise or an oil emulsion that does as much structural work as flavour work: it coats the filling and, critically, it waterproofs the inner faces of that delicate bread so a moist filling does not turn the crumb to paste. With artichokes this matters more than usual, because artichokes carry oil and moisture, and without the bind sealing the crumb the soft bread collapses before it reaches the hand. The bread, the dome, and the seal are the tramezzino; the artichoke is what fills this one.
The craft is the filling prep and the bind, because the bread is fragile and unforgiving. The artichokes are trimmed and cooked tender, usually braised or used as good carciofi sott'olio drained well, then sliced or roughly chopped so they pack densely rather than sliding out in whole leaves. They are dressed with mayonnaise, or a lighter mix of oil with a little lemon and parsley, in enough quantity to film every piece and to spread thinly onto the bread itself as a moisture barrier. The filling is mounded toward the centre so the cut shows a high curved profile, then the sandwich is pressed gently, sealed, and the crusts cut away last with a clean blade so the soft edges are not crushed. It is cut corner to corner into two triangles and held only briefly before serving, because the whole point is fresh, cool, yielding bread. A good tramezzino is plump, the bread intact and faintly moist only where the seal allows; a sloppy one is thinly filled and flat, or made so far ahead that the bread has gone gummy through.
The variations are filling swaps and additions on the same crustless domed base, and each deserves its own article rather than being crowded in here. There is the version that pairs the artichokes with tuna, the one that adds sliced egg, the prosciutto cotto relative, and the plain crustless tramezzino as the reference build. Each is the same soft, bound, overfilled idea with one element changed.