The Choctaws did it with Mississippi mud. They smeared a freshly caught fish from the salt waters of the gulf or the fresh waters of Lake Pontchartrain with a thick layer of clay and baked it whole—head, tail, guts, and all—in hot coals. Once baked, the mud was split open, the fish removed, and its innards stripped out in one piece.
We can do a similar thing with a salt crust, since salt is easier to find in most kitchens than Mississippi mud. Antoine’s rest