"How is everything tasting?"
That is a recent innovation, and I think it sucks. Used to be, they'd ask "how is everything?", and that wasn't bad at all. The new version, however, implies that all they care about is the food, and not at all about the other parts of the dining experience...like, for example, the service.
I'll occasionally call the waiter on it, but most of the time I just grumble about the decline in customer service standards.