The Frontega chicken is a chain panini whose defining decision is to pull the chicken rather than slice it. The chicken is smoked and then pulled into ragged shreds, which matters because shredded meat takes a chipotle mayonnaise into every strand and packs into a flat, even bed across a focaccia rather than sitting as a slab that shifts when the sandwich is pressed. The smoke and the chipotle are the same flavor argument made twice, and the pulled texture is what lets that flavor reach the whole sandwich instead of staying on the surface of a cutlet.
The craft is in the bread and the press. Focaccia is an olive-oil-rich flatbread with an open, slightly chewy crumb, and it is built to be heated under a panini press: the oil in the dough crisps the outer face while the inside stays soft, so the bread carries a moist filling without going limp. The pulled chicken is layered with melted mozzarella, which is chosen for stretch rather than sharpness so it binds the shreds without competing with the smoke, then tomato and thin red onion for the cold, acidic counter a rich filling needs. The chipotle mayonnaise does double duty as the heat and the binder, applied to the bread so it does not pool out under pressure. Pressed warm, the cheese fuses the loose chicken into a single mass and the focaccia compresses to it rather than fighting it, which is the difference between a built sandwich and a pile that falls apart at the second bite.
The Frontega sits in the broad American fried-and-grilled chicken sandwich family, where the close relations differ by how the chicken is cooked and what carries it. The fried-fillet build mounts a breaded cutlet on a soft bun with pickle; the Nashville hot version lacquers that crust in cayenne; the Buffalo build borrows wing sauce and blue cheese; the Korean-American style double-fries for a glassier shell. Each of those is its own sandwich and deserves its own article rather than being crowded in here.