Peixinhos da Horta.

This is one of the very few Portuguese dishes whose descendants are more famous than the original. The widely accepted account is that Portuguese traders and Jesuit missionaries in Nagasaki during the sixteenth century brought battered, deep-fried vegetables with them, cooked on the church calendar's abstinence days. The Latin term for those periods, quatuor tempora — the Ember Days — is generally given as the source of the Japanese word tempura. Japanese cooks refined the technique into something lighter and more precise over the following centuries, until tempura became a Japanese art form in its own right and the Portuguese ancestor faded into a home-cooked appetiser. The etymology is the standard explanation and rests on reasonable evidence, though the fine detail of who cooked what for whom in Nagasaki is not the kind of thing that survives in documents.

In Portugal the dish never went upmarket, and that is part of its charm. It belongs to Lent and to Fridays, to a cuisine built around Catholic fasting rules that shaped an enormous amount of Iberian cooking — and to the practical reality of a country where inland households had ready access to a vegetable garden and much less access to fresh fish. Flat romano beans are the traditional choice because their broad shape genuinely resembles a small flat fish once battered, which is the whole gag.

Today they turn up as a petisco — a small plate to eat with a drink — in tascas and at family lunches, usually piled on a plate with lemon wedges and eaten standing up before anyone sits down. Some cooks add a pinch of baking powder or a little beer for extra lift, some leaven the batter with yeast and let it rest an hour, and the argument over whether egg belongs in the batter at all is ongoing and unresolved. All of them agree on two points: the batter must be cold, and the beans must be eaten within about ninety seconds of leaving the pan.