I have been looking for years for a restaurant that serves better vegetarian food than I can cook at home. And I think I've found it at Canteen on Clifton Street. We've now eaten there twice in the evening, and last night being Burns night they served veggie Haggis with neeps, tatties and braised red cabbage which was delicious. But it was exceeded by my pannetone bread pudding with white chocolate sauce, the best pudding ever!
If you are searching for good vegetarian, give them a try, they even cook lovely meat dishes according to my partner. But you may have to book as they seem to be very busy.