Jelly omelette

Looking online at a number of early-mid-20th-century restaurant breakfast menus today, I see many feature something called a ‘jelly omelette’. Apparently it’s just that, an omelette where the filling is jelly, spread evenly across the surface of the omelette before folding it over in half, and finishing cooking. Kinda weird, but nevertheless, it does sound interesting; I intend to try it sometime, and see if I like it.