The Sandwich Grec is the most-eaten street sandwich in modern France, and it is essentially never Greek. The name is a Parisian mistranslation that stuck: a vertical-spit Turkish döner, shaved into a folded galette or a baguette, dressed with frites, salad, and a white garlic-mayonnaise sauce known as sauce blanche. It arrived in France with Turkish immigrants in the 1970s, took on a French personality through the 1990s, and by the 2010s outsold both the jambon-beurre and the burger by volume in the major urban centres.
The sandwich's structure: a fast-food architecture you can argue with. Spit-roasted meat (the standard is veal or chicken, the high end is lamb, the budget version is reformed-and-pressed); shaved thin; assembled in a pre-warmed flatbread; topped with a layer of frites that go inside the sandwich rather than next to it; finished with sauce blanche, sometimes harissa, sometimes ketchup, sometimes barbecue. It is the rare French sandwich where the cook's job is to keep volume steady at the lunch peak, not to refine the ingredients.
The regional and ethnic cousins extend the same idea. The Sandwich Merguez — the Maghrebi spiced lamb-and-beef sausage on a baguette with onion confit and harissa — is older in France and lives more often at the open-air market than the kebab counter. The Sandwich Falafel — Levantine fried chickpea balls in pita with tahini, pickle, and cucumber — is most associated with the Marais district of Paris, where the L'As du Fallafel queue has been on travel-guide pages since the early 2000s. Together these three sandwiches are the French city street-food trio that the classic boulangerie-charcuterie tradition somehow forgot to anticipate.