I don't know Nottingham that well but I would have said the Alley Cafe - has it already closed?
Have your friends asked you to find somewhere? As personally, as someone who is probably coeliac and has a severe gluten reaction, I would really rather do my own research than trust someone else, however well meaning they are. And unless I'm pretty damn sure that the place looks like it knows what it's doing, I'd much rather make something myself, it's not worth the risk.