The defining decision in this sandwich is using whole chicken fingers as the protein instead of a single flat fillet. Three fried fingers are laid across a buttered bun with lettuce, tomato, and a tangy mayonnaise-based sauce, and the gaps between the fingers are the structural fact everything else has to answer. A single breaded fillet seals into one flat plane; three separate fingers create ridges and channels, more crust surface and more places for sauce and bread to shift, so the build is engineered around managing a segmented protein rather than a continuous one.
The craft is in the contrast and in stabilizing those segments. Each finger is brined for moisture, breaded for a craggy shell, and fried hot, then the three are arranged in parallel across the bun so the bite is even rather than thick at one finger and empty between the next. The bun is toasted with butter, which firms its surface so it does not go soft against the warm fingers and adds a fatty note under the salt of the crust. The sauce, a thick tangy mayonnaise-based dressing, is spread on the bun rather than poured over the fingers, so it lands in the channels between them and seasons the bite without drowning the coating that is the entire point of frying them. The lettuce and tomato are the cool, acidic counter to a hot, hard, salty protein, applied in a volume the segmented stack can carry without sliding apart in the hand.
The variations are narrow because the form is narrow: more fingers for a larger build, the same fingers in a wrap, or the sauce dialed up or swapped at the counter. It sits inside the broad American fried chicken sandwich, which is at heart a structural argument about keeping a crust crisp inside a closed sandwich and runs that argument through chains, the Nashville hot version, the Buffalo build, and the Korean-American double-fry. Each of those is a codified style with its own partisans and deserves its own article rather than being crowded in here.