Unusual for me to do so, but I can think of two occasions.
Once, I was at a Country Club with some friends, and the waiter brought bread with a garlic butter. Tried it, then called the waiter.
" That´s not butter; it´s margarine".
"No, it´s butter!
" No it´s not. Ask the chef"
5 minutes later:
" Chef says sorry, it is margarine"
The second time, we were in an Italian restaurant and I ordered penne all arrabiata. I got a dish with tomatoes, ham and bacon. No hot peppers. So I sent it back.
Waiter: "The chef said this was his version"
Me: " The chef is barking up the wrong tree. This is more like an amatriciana"
He got it right the second time.