You should have asked cos they may have been able to make you something.
If you think about it, it gives them a chance to use a bit of creativity that ordinarily they aren't able to do. I'm sure the cooks there would love the chance to act like real chefs and have some input in the meals. I know when they made me a meal, the waitress was very chuffed with what they managed to make for me.
Maybe I was just lucky that the waitress was very knowledgeable about vegans, but you never know unless you ask.
Bookmarks