The oyster po' boy carries the most fragile filling in the family, and the entire build is a race against the oyster steaming itself soft. Fried oysters are not a cohesive fillet but a loose pile of separate pieces, each a brittle coating wrapped around a liquid, briny center. The moment they leave the oil they begin to soften from their own moisture, faster than almost anything else a fry kitchen handles. So the defining fact of this po' boy is timing: it is engineered to get hot, crisp-shelled oysters into the loaf and into the hand before the crust can give way.
The craft is a frying problem set inside a bread problem. Shucked oysters are dredged in a light seasoned cornmeal or corn-flour coating and dropped into hot fat for a short, decisive pass, long enough to set a crisp shell, short enough that the inside stays just-set and plump rather than overcooked to rubber. They go into the loaf immediately, in a heap, because a pile of small fried things sheds crispness the instant it sits. The thin-crusted, glass-crackly New Orleans loaf earns its place here precisely because it adds no moisture of its own and shatters cleanly instead of crushing a delicate filling. Dressed means shredded lettuce, tomato, pickle, and mayonnaise, applied so the cool and acid land on the oysters without flooding the bread, often with hot sauce or a remoulade worked in. The build is deliberately spare, because anything that adds wet to the loaf shortens the few minutes the crust has.
The variations are codified rather than chaotic. The Peacemaker, the la médiatrice, runs fried oysters in a hollowed, butter-crisped loaf as a peace-offering sandwich; a half-and-half order pairs oysters with fried shrimp in one loaf. The remoulade dress and the hot-sauce build are standing local choices. Those forms, along with the rest of the po' boy family of shrimp, catfish, and roast-beef debris, are their own sandwiches and deserve their own articles rather than being crowded in here.