Tramezzino Tonno e Pomodoro

In a Milanese bar in July the case holds a row of triangles labelled tonno e pomodoro in green pen, and by lunch the cook is replacing them with a fresh row built that morning. The summer tomato is what forces the turnover. Inside the triangle the tuna and mayonnaise lie as a pale spread along the lower slice, and a single ripe tomato disc shows red across the cross-section, bringing a sweet juicy lift the bound spread can never produce on its own. That same lift is a slow leak. A ripe tomato is heavy with cellular fluid, and the moment the knife opens it the juice starts to run, which is why the cellophane case behind the glass exists in part to slow the point at which the brightness starts costing the bread.

So the build is a race against the slice's own water, and it is won before the bread is touched. The tomato is picked ripe and firm, not soft; the inner pulp and seed mass are scooped out along the cross-section with a teaspoon; the wall slices that remain are laid on a paper-lined board and salted lightly. The salt draws a little juice within two or three minutes, and the slices are blotted between two cloths until the surface is matte and the paper underneath turns no further pink. Only then does the fish go in, folded with a touch less mayonnaise than the plain version takes, because the slice still brings moisture even after blotting and a firmer spread can stand it. The spread is laid first against both inner crumbs, the slice set centrally on the lower face: mayonnaise underneath films the bread, spread above shields the upper crumb, and the tomato sits bracketed by fat on both sides.

The failures are specific and fast. A tomato sliced too thick puts a wet slab against the bread and the lower face goes pink within the hour. A tomato seeded carelessly keeps its watery pulp and weeps even after salting. Skip the salting and the slice carries its full water load straight into the cross-section. A bland underripe tomato brings no sweetness to weigh against the rich spread, and the triangle reads as soggy fish with a pink disc through it. A working version uses the day's ripest firm tomato, seeds and salts and blots it, lays it into the fat seal, and gets the wrapper on within five minutes of assembly, before the clock the tomato started can run.

Lift one off the case and the cross-section gives the bite away before the first taste. The pale bread yields without resistance, the spread under it dense and cool and faintly fishy, and then the tomato lands with a soft wet snap and a bright vegetal sweetness that cuts straight up through the mayonnaise. There is no crust and nothing toasted; the texture is all softness, the tomato the single moist element against the close even crumb, the chill of the case still on it. A good one tastes of fresh tomato and cured tuna in balance and leaves no wet patch on the paper saucer. A tired one has gone faintly pink at the seam and tastes mostly of damp bread.

The bar grammar around it is brief, and the close relatives each go their own way. The triangle is asked for at the case as tonno e pomodoro, never as a tomato tuna sandwich; the cook lifts it with metal tongs onto a paper saucer with a half-glass of white beside it. In Trieste it picks up a leaf of rocket and becomes tonno, pomodoro e rucola; in Verona a few capers go through the spread against the tomato's sweetness. Swap the disc for a leaf of lettuce and the lift goes drier and bitter with no moisture problem at all; swap it for a marinated artichoke quarter and it is a cured, fully different triangle; drop it and the build returns to the unadorned tuna baseline. In Naples the same idea is built on a panino con tonno e pomodoro in a soft sesame roll, a different bread and a different sandwich. Above all this one is read against the season: outside July to September a Padua bar will tell you the tonno e pomodoro is on hiatus until the market gives them tomatoes again.

A post-war filling on a 1925 form

The triangle itself dates to 1925, cut at a marble-counter bar on the Piazza Castello side of Turin, the Caffè Mulassano. Angela Demichelis Nebiolo and her husband Onorino, two Piedmontesi back from running restaurants in Detroit, had bought the room that year and trimmed the crusts off soft white bread pressed in an American toaster they carried home. Gabriele D'Annunzio supplied the word a few seasons later, building tramezzino on tramezzo, the partition, and La Cucina Italiana printed the first national recipe in July 1936. The tomato-and-fish filling is not on that early list.

It is a post-war addition, one of the case fillings that arrived with the canned-tomato boom and the spread of oil-packed tuna across northern Italy through the 1950s. It belongs to the modern bar case rather than the founding form: a row of about a dozen named two-ingredient combinations the cook stocks fresh each morning, of which this is the wettest and so the one replaced twice a day in summer when ripe tomatoes are available to build it at all.

In 1999 the Piedmontese tramezzino was added to Italy's official PAT inventory of traditional regional products, the agriculture ministry's national list, where the 1925 Turin form takes its place among the country's older specialities. The tuna-and-tomato filling holds no listing of its own; it rides on the form's, a seasonal variation on a recognised base rather than a documented original, and its honest claim is exactly that, a summer filling without a founder, fixed in time only to the post-war decades that gave Italian bars the canned tomato in the first place.