Bocadillo de Calabacín

Salt the courgette before anything else. Cut into rounds or long ribbons and scattered with salt, the slices bead with water within minutes, and they have a great deal of it to give, because a calabacín is mostly water held in pale, mild flesh that carries almost no flavour and almost no fat of its own. Blotted dry, the slices go onto a grill or into a film of hot oil and are cooked harder than seems necessary, until they take real colour and their edges catch. That is the working premise of the whole roll: a near-empty vegetable that has to be given everything it lacks.

Grill or fry decides what kind of sandwich it is. Over a grill the slices come off drier and a little smoky, with clean charred stripes and a leaner taste. In oil they go softer, richer, and more tender, drinking up the fat as they cook. Either way they must be properly drained and properly seasoned before they reach the barra. A single thin layer simply disappears inside the loaf, so the slices have to be stacked enough to register, and the browning has to be real, because pale slices bring nothing to taste.

The two ways it fails both trace to handling rather than the vegetable. Underdrain the slices and they weep into the crumb until the lower crust turns translucent and the bread sags by the second bite. Underseason them and there is nothing on the palate but warm bread and a faint green note. Cook them gently and they stay pale and squeak against the teeth like a wet sponge; cook them hard and dry and they come off browned, tender, and faintly nutty. The oil rubbed into the crumb has to be enough to carry the seasoning but not so much that the loaf turns greasy.

In the mouth the first note is the oiled, toasted bread and the warm oil itself, then the slices, soft and yielding with a browned, gently nutty edge where the heat caught them, mild and clean under the salt. A scrap of mint or a clove of garlic rubbed into the crust lifts it; a squeeze of lemon sharpens it. The courgette's own taste is a quiet green background, present but faint, the build leaning on the toasted crumb and the seasoning rather than on the vegetable to be loud. It is a soft, warm, light mouthful, the lightest thing in the bread bin.

It is plain, cheap, everyday food, the meatless option on a bocadillería board next to the tortilla and the jamón rolls, often ordered by whoever wants something light or is skipping the meat. It is the kind of thing a Spanish home cook makes from a glut of summer squash and a length of barra, and it costs almost nothing because the vegetable is everywhere. No counter is famous for it; it is a quiet staple rather than a destination.

Almost every version is really a decision about what to add for savour. A slice of soft melting cheese or a few shavings of hard sheep's cheese is the commonest fix, lending the salt and fat the calabacín withholds; a sheet of roasted red pepper brings sweetness and colour; a fried egg binds the loose slices and adds richness. Its near twin is the aubergine bocadillo, the same approach applied to berenjena, a meatier vegetable that browns to more depth and needs less help. Load in lettuce, tomato, and egg together and it stops being a courgette sandwich and joins the broad cold bocadillo vegetal.

A Squash Bred Young in Milan

The courgette bocadillo carries no origin story, which suits a roll built on the cheapest, blandest vegetable in the market: it is simply what a kitchen does with a glut of summer squash and a loaf, and it left no record because none was wanted. The vegetable, though, is younger than its place on a Spanish table suggests. The squash itself is a New World plant, a Cucurbita pepo domesticated in the Americas, but the slim, tender, immature form eaten as courgette is a much later European refinement.

That tender green courgette is an Italian creation of the nineteenth century. Growers around Milan bred and selected summer squash to be picked young and small rather than left to harden, and the type is traced in the region to around 1850, with the earliest clear description of the zucchini as a distinct cultivated form appearing in a Milanese horticultural work published in 1901. What can look like an ancient Mediterranean staple is barely more than a century old as the vegetable now sliced into the roll.

In Spain it became cheap and ubiquitous, grown year-round under the greenhouse plastic of Almería and the southern provinces and stacked in every market, which is exactly why it ends up in a barra: not because it is prized, but because it is everywhere and costs almost nothing, a Milanese nineteenth-century cultivar turned into Spain's most ordinary meatless lunch.