Pan con tortilla is a sandwich whose filling is cooked to a thickness, not a recipe. The tortilla here is a Spanish-style omelet, eggs set firm enough to be cut into a wedge or a slab that holds its own shape, often with potato and onion folded in. That set is the entire point. A loose scramble would slide out of the bread and turn the crumb to mush; a firm omelet behaves like any other sliceable filling, stacking cleanly and giving the bread something solid to compress against. The sandwich lives or dies on how far the eggs are taken in the pan.
The craft is in the loaf and the timing. Cuban bread is split and the omelet is laid in warm but no longer running, so the eggs steam the inside of the crumb just slightly rather than soaking it. The loaf is frequently pressed or toasted, which crisps the thin crust and warms the omelet through without cooking it further. This is a quick build by design, a breakfast or a fast lunch assembled in the time it takes the press to close, and its restraint is the discipline: the omelet is the meal, and the bread is there to make it portable. Cuban bread suits the job because its tender, lard-enriched crumb gives way to a soft filling instead of fighting it, while the crisped crust supplies the only real bite in the sandwich. Built right it is dense and clean, the wedge of egg holding together inside a thin, crackly shell rather than smearing across it.
Pan con tortilla sits in Miami's pressed Cuban and Florida Latin family, each a different build on the same loaf. The Cuban runs roast pork, ham, Swiss, and pickle under the plancha; pan con bistec uses pounded steak and shoestring potatoes; pan con lechón runs citrus-mojo roast pork; pan con minuta runs a fried fish fillet; the medianoche moves the Cuban onto a sweeter egg roll. Each is a codified build with its own logic and deserves its own article rather than being crowded in here.