In terms of vegan foods there are a fair few, but mostly they're very expensive and sweet. We don't have a kitchen, and the only things we could buy was vegetable stock. Then when we were at the till I asked if I could use the toilet. They explained that there was a staff toilet, but that I couldn't use it.
Not really sure what the purpose of telling me there's a toilet but I can't use it, that was pretty frustrating.
But they do have a large selection if you do have a kitchen.
Very few non-dairy fortified milks.