This false pepper is harvested late in the year from a tree which grows spontaneously in the mountainous areas of the Indochinese peninsula. It comes from Vietnam. It is called "mountain pepper", not because it is found on the high peaks, but because it grows in the treetops.
French settlers called it "flower pepper" and the English "Indian Prickly Ash".
It is a close relative of the Chinese Sichuan and Japanese sansho "peppers", but it is much finer, more elegant and easier to use than either. Also it doesn't have the anaesthetic effect of the Sichuan.
Can be of course used with sea food, crustaceans, fatty fish but also with meat such as guinea fowl, pigeon, lamb, sweet and sour pork and a nice side of veal. You can successfully use it in soups, broths, with steamed vegetables, button mushroom salads, caramelized chicory. It will subtly enhance fresh goats' cheese with a little olive oil.
It will surprise your guests in fruit salads, fruits poached in wine, mousses, ice creams or sorbets. It goes especially well with pineapple, red fruits, citrus fruits, and can be astonishing with chocolate.
It works surprisingly well everywhere in fact.
Avoid cooking it. Use it at the last moment with a fine grind.