[kekub]

I always recommend https://qrmenucreator.com/ to restaurant owners. I feel it is simple enough for them to get started, gives features like instant changes and comes with a sane default layout/ui and is free of charge. Payment and ordering would still be done in the classical way, but you get the chance to at least have an always up to date menu with the possibility to reflect when something is sold out or temporarily unavailable.