When you make your reservations, and again when you check in at the podium, let them know you have a "food sensitivity". Normally the chef or someone else will come out from the kitchen to discuss the foods with you. Based on what you tell that person, you will get suggestions of anything you should not eat; if it is a buffet and a large number of items cannot be done they will prepare a special meal for you.
There is a lot of discussion on this in the "disABILTIES" forum.