The Falafel Sandwich (ساندويش فلافل) is the canonical form of this whole family: fried chickpea balls in Arabic bread with tahini sauce, tomato, lettuce, pickles, and pickled turnip, rolled tight. The angle is balance through opposition. Every element is there to fight the one next to it. The fritter is hot, dry, and rich; the tahini is cool, loose, and nutty; the tomato and lettuce are wet and fresh; the pickled turnip and sour cucumber are sharp and acidic. None of these would make a sandwich alone. Together, in the right proportion, they hold each other in tension. Get the ratios right and every bite carries crisp, creamy, fresh, and sour at once. Get them wrong and one note swallows the rest, usually the chickpea going heavy or the sauce going pasty with nothing to cut it.
The build is short and the order is not arbitrary. Thin Arabic flatbread or a pocket pita is laid out and given a base layer of tahini sauce whisked with lemon, garlic, and water until it pours. The falafel goes in hot, often broken or pressed flat so the craggy interior soaks up sauce instead of rolling dry. Then the fresh layer, tomato and lettuce or cabbage, mint or parsley, and the sharp layer, pickled turnip and sour cucumber pickle, sometimes raw onion or a chili paste. More tahini goes over the top, then the bread is rolled or folded tight and often pressed briefly on a flat-top so the package seals and takes a little color. A good falafel sandwich holds a shell that crackles against a moist green crumb, a tahini coat that is sharp with lemon, and enough pickle to keep the richness in check. A sloppy one is a soggy tube where the fritter went limp, the sauce pooled at the seam, or the only flavor is heavy chickpea because the acid was missing.
It varies by what gets added to or substituted into the core. Fries packed inside, hummus used as a spread instead of a sauce, a heavier chili load, the choice between an all-chickpea or a chickpea-and-fava fritter, and the swap between thin flatbread and a thicker pocket are all recognized moves, and a plated, unwrapped presentation is its own thing again. House styles also matter: a particular shop's spice mix, sauce sharpness, and pickle ratio can make its sandwich identifiable on taste alone. Each of those is a recognizable form in its own right and deserves its own treatment rather than a footnote here. They all return to the same idea: opposed elements held in balance and sealed in bread, judged on whether the tension held.