The egg kathi roll is the Kolkata anda paratha roll: a paratha cooked with egg spread on top while it is still on the griddle, then rolled with onion and chutney. The signature is that egg and bread are cooked as one piece, the paratha griddled, beaten egg poured over it, and the two pressed together so the egg becomes a layer set into the flatbread rather than a separate omelette laid inside. The angle is that flake-and-egg union, which is what separates a proper kathi roll from a plain wrap with egg stuffed in.
The build is exact. A layered paratha is heated on the tawa until it begins to crisp and flake, beaten egg is poured across the hot surface, and the paratha is flipped onto the egg so it sets bonded to one face. Off the heat, sliced raw onion and a line of chutney are laid down the center, and the paratha is rolled tight and usually paper-wrapped for the hand. Good execution shows a paratha that stays flaky and structured under a thin, fully set egg sheet welded to it, sharp onion for contrast, and chutney spread the length of the roll. Sloppy execution means egg poured onto an underheated paratha so it slips off in a slab, an egg layer overcooked tough, a paratha gone limp and greasy so it cannot hold a roll, or chutney bunched at one end.
The egg kathi roll shifts by chutney and by additions to the egg or the wrap. Some stalls scatter chopped chili and onion onto the wet egg so they cook in, add chaat masala or lime, or layer in a second egg for heft. Building shredded chicken, kebab, or paneer into the same paratha makes it a filled kathi roll, a different preparation that deserves its own article rather than being crowded in here. The constant is egg cooked into a flaky paratha and rolled tight, and no chutney or seasoning rescues a roll whose egg never bonded or whose paratha collapsed.