Gyros Arni (Γύρος Αρνί) is the lamb version of the spit-roasted sandwich: arni, lamb, marinated and stacked on the vertical cone in place of the usual pork or chicken. The angle here is the meat itself. Lamb is fattier, more strongly flavored, and more expensive than pork, which is why it is the less common cone in Greece and why it turns up more often in the diaspora, where lamb reads as the expected gyros meat. Anyone ordering it is choosing a deeper, gamier sandwich, and the build is tuned around managing that richness rather than fighting it.
The construction follows the standard spit order but the variable that matters is fat handling. The lamb is marinated, layered onto the cone, and roasted as it turns; the cook shaves the crisped outer edge in thin slices as each layer renders. Lamb throws off far more rendered fat than pork, so two things separate a good gyros arni from a greasy one: the slices must be thin and well-crisped so the fat browns rather than pooling, and the pita, griddled soft and pliable, has to be built fast while the meat is hot or the fat congeals and turns the wrap heavy. Tzatziki and raw onion are doing real work here, the garlic-yogurt cutting the lamb and the onion's sharpness keeping it from sitting flat, with tomato for acidity and fries for bulk. The failure modes are the lamb-specific ones: undercrisped pale slices that taste mutton-heavy and chewy, a wrap gone slick because the meat cooled before assembly, or a timid hand with the tzatziki that leaves nothing to balance the fat. A good one tastes unmistakably of lamb, charred at the edges, with the yogurt and onion holding it in check.
It shifts mostly by source and seasoning. In Greece a lamb cone is a deliberate, often pricier choice and tends to be seasoned in the local style; in Greek communities abroad it is frequently the default, sometimes blended with beef, and seasoned closer to a Middle Eastern profile. The plated lamb version served without bread, the mixed-meat cone, and the standard pork gyros each operate on the same turning-spit logic but are distinct enough to deserve their own articles rather than being crowded in here. What is constant for gyros arni specifically is that the sandwich lives or dies on whether the cook respects the fat: crisp it, build hot, and let the tzatziki do its job.