I think if a unicycling restaurant existed in Las Vegas, we would have heard about it. I can think of a number of reasons why one would not exist in this country though. not to be a naysayer, but:
Liability. If a patron ever gets injured by a cycle or waitperson (only a matter of time), they’ll have a hell of a time protecting themselves.
Slippery floor. Ever notice how much slippery stuff can get on restaurant floors? Bad for tires. Carpet would solve that, but unicycles a) handle poorly on carpet and b) would tend to track spills and other stuff around to good parts of the carpet.
Finding employees. Ever work as a waitperson? I haven’t, but I’ve seen what’s involved in carrying large trays full of food around. You could not have entry-level riders doing any part of the job in a crowded restaurant. Restaurant turnover, I assume, is fairly high. Unicycling waitpersons would have to be paid a premium to keep them around, which would be reflected in food prices.
Bummer. It would sure be cool to eat there!
But you still have a chance. There is a restaurant somewhere in Thailand (Bangkok?) that has unicycling chicken-catchers. I’ve seen this on TV so I know it’s real. I do not know if the place is still doing this though. I think it’s like a rotisserie cooking process. When your chicken is done, it is catapulted into the air (the restaurant is open air), and caught by a waiter on a unicycle. He retrieves the chickens on a silver platter, and supposedly rides to your table with it. Happy chicken!