Since he's a chef, maybe he makes his own mayo (which would be a superior version at least). Ketchup on steak I can understand, since it's often an ingredient in steak sauces.
There's a place I frequent here that has premade vegetarian sandwiches, and lately they've taken to adding mayo to nearly all of them - ugh! Only 1-2 sandwiches there are now made without mayo. Why, oh why?
