It is pale-coloured and boneless. It is only lightly-salted.
The meat used is not allowed to be frozen first; it must be fresh, and be “superior” or “choice” grade. The bones are removed, then the meat is cured in a salt brine, then pressed into a rectangular-shaped mould.
It is then steamed in an aromatic broth, spiced with juniper, coriander, cloves and a bouquet garni.
It is supposed to be sliced only as it’s being sold, but you can indeed buy packets of “prétranché spécial sandwich.”
You can ask for it sliced paper thin for sandwiches, or in thicker slices so that you can dice it for recipes.
Despite its name, it can be made anywhere — production is not restricted to Paris.