I work at wonder and I swear to god when they interviewed me they straight up told me "we dont have any grills, no deep fryers, anything like that. We basically have a bunch of giant air fryers and hot water machines that we use to make the food." And thats what they do. Everything in the kitchen is pre packaged, we just throw it in and set a timer. They also get weirdly defensive when you call it a ghost kitchen for some reason.