Tramezzino al Tonno

Walk into a bar on a side street in Padova at eleven in the morning and the row of tramezzini in the glass case is already labelled. Tonno. Prosciutto cotto. Carciofini. Insalata russa. The plain tuna triangle is the first one bought, the one a regular orders without looking at the case, and it is the build the other tuna versions stack on top of. Two ingredients. Drained oil-packed tuna. Mayonnaise. Pressed inside two soft pancarrè slices with the crust shorn off. Nothing else. No leaf of lettuce. No tomato. No caper. No boiled egg. The whole bar pricing of the form turns on this triangle being the cheapest and the steadiest seller in the row.

The two ingredients hold each other up. Mayonnaise alone in soft white bread reads as wet paste. Tuna alone falls out of the cut face. The fold of the two is one cohering mass that the bread can carry to the hand without spilling, and the salt of the fish and the fat of the bind reach all the way to the diagonal points. Drop the bind and the bread soaks; drop the fish and the bind has nothing to flavour. The build is two halves of one decision.

The whole sandwich runs on three numbers being right. The first is how hard the tuna is drained: lifted from the tin with two prongs of a fork, the packing oil tilted off into the sink and the flesh given one firm press against the side of the tin, but not squeezed flat or it goes to dust. The second is how much mayonnaise: enough to make the flake cohere and no more, the spread held together when a spoon scoops it but not slack. The third is how the bread is filmed: a thin coat of the bound mass pressed against both inner crumbs as it goes on, so the spread does double work, the bind and a moisture barrier in one gesture. Hit those three and the wrapper comes off four hours later to a triangle that still holds its diagonal. Miss any of them and the case shows a slumped soft thing by lunch.

The base bread fails in two specific ways. Loaves left over from yesterday lose enough water to read as cardboard against the soft bind. Loaves cut too thin let the bind soak through the upper face inside an hour and the triangle goes grey at the centre. Cut too thick and the diagonal turns to two slabs of bread holding a thin smear, and the fish stops doing its work. The pancarrè has to be the day's, the slice at standard thickness, the crust gone with one quick cut. The pile of trimmed crusts on the steel counter at a good Italian bar at nine in the morning is a useful sign.

The plain version is the triangle a regular orders without speaking. The wrapper is peeled back and the triangle disappears in three bites at the counter, washed down with a glass of vermentino or a prosecco. A second is ordered to follow. The shape goes into the lunch bag of a child in Verona, into the wrapper a Roman commuter eats on the Frecciarossa, onto the saucer beside a Venetian spritz. The base does not arrive at the table announcing itself. It is the wallpaper of the form, the one that is always there, and the cook judges every other filling against it.

Closer relatives each have their own treatment. Add salted capers to the mix and the salt comes from the brine instead of the fish; add a tomato slice and the moisture problem changes everything; add olive and the cured note picks up an edge; chop hard-cooked egg into the bind and the spread thickens into a different salad altogether. The tuna and tomato, the tuna and olive, the tuna and artichoke, the tuna and egg are each their own entry in the catalogue. They are read against this one. Strip them all away and what is left is two ingredients in soft white bread, which is enough.

Origin and history

The triangle itself is a 1925 Torino invention. Caffè Mulassano, a small marble-clad bar on Piazza Castello, was bought that year by Angela Demichelis Nebiolo and her husband Onorino Nebiolo, returning Piedmontesi who had spent two decades running restaurants in Detroit and brought back the American pull-toaster and the soft sliced white pancarrè to put through it. The two of them began assembling small crustless triangles from the toasted slices as an answer to the English tea sandwich.

The name came from a regular at the bar. Gabriele D'Annunzio, an Abruzzese poet and political figure who used Mulassano as one of his Torino haunts, took to calling them tramezzini, his Italianisation of tramezzo, the in-between, against the loanword sandwich. The first national recipe entered print in July 1936, in La Cucina Italiana, which described a butter-and-anchovy filling closer to the English original than to the Italian forms that came later.

The mayonnaise-tuna filling is one of the post-war Italian additions, picked up out of the same logic that put oil-packed tuna into every Italian larder by the late 1950s. By the time the tramezzino case became a fixed feature of the Italian bar in the 1960s, the unadorned tuna triangle had become the volume default it remains. Mulassano still serves them on the marble counter at Piazza Castello 15, with the pull-toaster Onorino brought from Detroit in 1925 still on the back wall.