Feta Cheese (Φέτα) is exactly that, and on this catalog it is a component rather than a sandwich: crumbled feta added to Greek pitas and sandwiches. It earns a page because feta in a pita is not a topping that quietly rides along. It is a strong, salty, acidic brined cheese that reshapes the whole bite, and whether it improves a build or unbalances it comes down to how much goes in and what it goes in with.
The role is to add salt, tang, and a creamy-crumbly texture against grilled meat and raw vegetables. Good practice is real Greek-style sheep or sheep-and-goat feta, crumbled rather than sliced so it disperses through the pita, and dosed with restraint because it is already heavily salted from the brine. In a souvlaki or vegetable pita it does specific work: its acidity cuts grilled fat, its salt lifts tomato and onion, and its texture gives the wrap something soft and cool against hot meat. The failure modes are clear. Too much feta and the pita reads as one salty note with everything else flattened underneath; pair it with an already salty, olive-and-cured-meat build and the salt stacks past the point of pleasure. Dry, crumbly industrial feta that has lost its moisture adds salt without the creaminess that makes it worth having. And feta plus tzatziki plus grilled fat is a lot of richness in one wrap, so one of those usually has to yield. A careful build lets the feta be a clear accent, present in most bites without burying the meat or the sauce.
How it shifts depends on the rest of the assembly and the regional leaning. Some pitas use a generous crumble as a near-co-lead with the meat; others use just enough to season. A softer, wetter feta melts slightly against hot fillings and turns creamy; a firmer one stays in distinct salty crumbles for contrast. Feta is also central to dishes well beyond the pita, the rusk-based dakos and the baked cheese pies among them, but those are their own preparations and deserve their own articles rather than being crowded in here. As a pita and sandwich component, the rule holds: good brined feta, crumbled, and used as an accent rather than a flood.