The menu lists chicken nuggets, grilled cheese, and a fruit cup as choices on the children's menu for lunch. Those selections technically aren't offered for dinner, since it's a buffet. But if you contacted Disney dining and explained your son's situation, I wouldn't be surprised if they could provide some of those choices to your son at dinner, as they make every effort to be accommodating to those with special needs. It can't hurt to ask, if the buffet looks good to the rest of your party. And there is mac and cheese on the buffet.