A recipe column in the Times incipits thusly:
Pissaladière is one of my Desert Island dishes, a pizza-esque onion tart from Nice that is recognisable by its anchovy lattice studded with black olives. Its name comes from pissala, a Provençal word for a Niçoise fish sauce made from fermented anchovies and sardines. This sauce, now replaced by canned anchovies preserved in olive oil, is linked to Ancient Roman liquamen, one of the earliest seasonings.
I’ve never heard of pissala before, and to judge by the various email discussions of garum and liquamen I’ve seen through the years, most of my readers probably haven’t either, so folks might want to check out the only real recipe for it that I found for it in my quick scan of the net … another site claims that the strong fish taste survives more than in “earlier Roman fish sauces”, but I’m not sure what they base that on … Whatever the case, the recipe seems easy enough (as does the recipe for Pissaldiere, which looks very much like one of the pizzas my Sicilian mother-in-law makes) … perhaps some brave teacher might do this as a class project?