Food Assembly Line

You put your bank or credit card in a machine like an ATM, punch in the things you want, including all extras, and then press Start. The machine debits your card, spits out a receipt with a number on it, and you go watch the machine in action as it assembles your order along a visible (behind glass) assembly line.

Say it's a hamburger (though it could be salads or subs or whatever). A camera at each assembly hamburger ingredient station would capture the action in closeup. At your table, you could watch a monitor showing your order being assembled ingredient by ingredient. If you ordered more than one thing, you could split the screen or focus on one item.

Or you could watch it live: follow your burger down the line (it's safely behind glass) to the automatic wrapping stage and bagging stage. Multiple items in one order would be herded together until all are ready for the bag.

If the action wasn't lively enough, you could work some Rube Goldberg variations into it. And the machine would play Warner Brothers cartoon music for factories (I think it's called Powerhouse).

A fancier version could run the food around the perimeter of the restaurant (or carry it on an overhead contraption) and deliver it to your table, maybe lowered by a mechanical hand at the end of an extended metal arm.

A simpler version could offer hot food (limited menu) straight out of the wall like an ATM. When your number displays, you know it's your turn to grab the bag coming out of the wall dispenser. (Though I notice now that the ATM thing is suggested in "Fast Food atm").