The farinata in panino is bread folded around bread, and that is the whole of its character. Farinata is the Ligurian chickpea pancake, a batter of chickpea flour, water, and olive oil poured thin into a wide copper pan and baked in a fierce oven until the surface crackles and the inside stays custardy. Slid hot off the pan and folded into a split roll or a length of focaccia, it becomes the most unapologetic carbohydrate-on-carbohydrate sandwich in the Italian repertoire. There is no protein and no filling in the usual sense: the farinata itself is the filling, and the bread is a second starch wrapped around the first.
The craft is the contrast of two textures that are nominally the same thing. A good farinata is not uniform: the edges go thin and almost crisp where they met the pan's heat, the centre stays soft and faintly liquid, and the chickpea flour gives it a savoury, mineral depth that wheat bread does not have. Folded into a roll while still hot, that soft, oily, just-set interior is what justifies the bread around it; the roll adds structure and a clean handle, and the olive oil already in the batter slicks the crumb so no further dressing is wanted. Pepper is the only thing that goes on it in the Genoese habit, sometimes a little more salt. The bread is plain and slightly chewy on purpose, because a strong loaf would compete with a filling whose entire appeal is its quiet, eggy chickpea softness.
The variations are Ligurian and narrow, and the wider family keeps its own pages. There is the rosemary-and-onion farinata, the thicker Tuscan cecìna, and the broader split focaccia tradition into which the same pancake is sometimes folded. Each is a different chickpea or oiled bread argued in its own town, and each deserves its own article rather than being crowded in here.