Hmm, salt. Not great for you in vast quantities but so good in things like anchovies and olives. Usually we have a bottle of anchovies on the go and olives are always kicking around in the fridge. Both got used in the pissaladière I made the other night.
It hardly needs a recipe. All you do is unroll some pastry into a pie tin (and, once again, let me put in a good word for the ready-to-roll pastry I can buy here). On top of that goes a thick layer of onions that have been cooked and cooked and cooked for ages over low heat so they become brown, soft, sweet and unctuous. A latticework of anchovy fillets on top, olives where they join and it all goes into the oven for half an hour at mark 7. We ate it with the last of the tabbouleh left over from dinner the other night.