I love responding to this type of thread as a person who changed from "screw you hit the door" to how can I make you happy to be here.
We are a caterer, so we don't comp at all, since we are paid 14 days prior to the event whatever we produce is what they get and with no outstanding balance they have little leverage to make a false claim.
That said about five years ago when the special diets starting showing up I was in the "Show them the Door" camp. Especially since we are a caterer and don't usually have a full on kitchen at the location.
But I started listening to people and found that if I could pull something together we got good "word of mouth" out of meeting the accomodation. So I take my butane burner, copper saute, and a large portabella along with a nice piece of salmon to every function. The times I have had to pull it out and use it in one year maybe numbers 12 at most.
But the reaction from the requesting party is fantastic. They are so use to being told to pound sand that it floors them I can put a plate together for them.
To me, it is my job....... it is what I do..... and I like doing it so I won't insult a client, I will meet the need anyway possible. And I cook on the fly well enough to pull it together on a butane with no problem.
If you think the allergy thing brings a reaction..... let me tell you about my work to perfect the "Well Done" steak. You can not believe how many pros rant about cooking well done. It ruins it..... well maybe if you are incompetent at cooking it ruins it, but I started working with the steaks and created a technique that turns out a moist well done steak. And I have the letters to prove it makes them happy that a chef actually took a professional interest in producing a professional quality well done steak.
Laugh.... but I am banking the profit from people who recommend us cause I did not go on the "MANDATORY" chef ego rant about well done steaks. Now when one of the chefs starts ranting, I tell them... move over let a pro do it.....