Tartine Gratinée

A single slice of country bread goes under the broiler heaped with grated cheese, and in two minutes the salamander turns the top to a blistered, lacquered crust while the kitchen sends it straight out. That is the tartine gratinée: an open-faced slice taken to heat, a layer of bread on the bottom and a layer of melted cheese on top, eaten warm with a knife and fork at a counter. It is a sandwich the way an open-faced thing is, a bread base carrying a filling with nothing laid over it, missing the top slice that a closed sandwich would fold across. The lacquered cheese is the whole event, and the slice exists to hold it up to the flame.

Everything in the build answers to what heat does to one slice. The cheese has to be a melter, a Gruyère or Comté or Emmental grated so it flows and browns into a sheet rather than splitting into oil and rubbery strings the way a poor melter does under a hard broiler. The bread is the load-bearing problem, because a single slice has no partner bracing it: it needs enough crust and close crumb to crisp under the heat instead of going limp and sodden beneath a weight of molten cheese, which is exactly why a firm cut of pain de campagne carries it where soft white bread would collapse. Too thin a slice scorches through before the cheese browns; too thick and the center stays cold and bready while the top burns.

The slice comes off the heat in three states at once and starts losing them immediately. The top is blistered and brittle where the cheese caught the flame, the crumb just beneath has gone soft and hot, and the crust at the edge has hardened to a snap. Wait too long and the steam rising from inside softens the whole thing back down, the crisp top sweats and slackens, and what was a crackling slice becomes a damp one. This is why it is a fast slice, fired and run out, not a thing that survives a tray or a wait; the gratin is at its best in the minute after it leaves the broiler and is honestly ordinary five minutes later.

Lean over one as it lands and the smell is toasted cheese and warm crust, sharp and nutty off the browned top. The first cut through the lacquer gives a thin crack, then the fork drags up a string of cheese that has gone slack and ropey under the crust. The bite is hot enough to catch the lip, the blistered top crunching against the soft crumb below, the cheese coating the tongue with browned, faintly bitter edges where the flame reached it. The crust at the rim holds firm in the fingers while the center yields, the whole slice carrying the dry savor of cheese cooked just past melting, the point where it stops being mild.

This is bistro and counter food, the open slice a Paris kitchen can put under the salamander and fire out fast for a midday table, neither a breakfast tartine nor an apéro bite. It lives among the city's hot cheese-and-bread dishes and a diner orders it knowing it comes plated and forked, not wrapped to carry. Slip a slice of ham under the cheese before it goes to the flame and the slice tilts toward its closed, béchamel-bound relatives on the same menu, the gratiné edging into croque territory while staying a single slice.

The variations are the rest of the open-faced family, each a single change for its own moment. Serve the cheese cold and unmelted on the same bread and it is a plain cheese tartine, a room-temperature thing entirely; strip it back to bread and butter alone and it is the most basic tartine of all. Lay ham and butter along a split baguette instead and it is the café Parisian tartine, cold and unbroiled. What is genuinely a different dish, not a variant, is the croque-monsieur: two slices closed around ham and cheese, bound with béchamel and gridded or baked, a built sandwich rather than an open slice run under a flame, and it keeps its own entry.

The open slice and its closed cousin

No one invented the broiled cheese tartine and no year marks its start, since melting cheese on a slice of bread over fire is about as old as bread and cheese and an oven sharing a kitchen; the datable history sits with its closed, dressed-up cousin, which entered the record in a specific Paris year. The open slice is simply the plain form, the thing a cook does with leftover cheese and a heat source, predating any name a café gave a fancier version.

The two share a flame and split at the second slice. The tartine gratinée stops at one piece of bread and lets the broiler do all the work on an open top; the croque adds a lid, ham, and béchamel and becomes a built thing the open slice never was. A counter that serves both plates the gratiné in minutes off the salamander, the same heat the croque needs, the difference being only whether a second slice ever came down on top.

The croque-monsieur is the one with paper, and its record fixes the family to a place and a year. The name turns up in the Paris sporting press as early as 1891, but by the account folded into the Grand Larousse gastronomique the dish first appeared on a menu around 1910, at a café on the Boulevard des Capucines near the Opéra, ham closed inside bread and bound with béchamel before the grill, a few steps up from the open slice it grew out of.