I was very pleasantly surprised by two recent pub visits with excellent vegetarian (and non-veggie) food offerings. Teuchters Landing (formerly the popular Waterfront) has a "mug" menu of hearty, extremely tasty food served in small or very substantial mugs.
I had a vegetarian haggis stovie (priced at a little under £5) which was a savoury stew of said haggis and veggies and was astonishingly good. It was sampled with vocal approval by meat-eaters and veggies alike at the table.
A dining companion had a lamb stew which he couldn't praise enough. According to him, it was chock-full of a whole baby lamb with a few vegetables to round out the very good flavour.
Others had a gorgeous cauliflower, carmelized onion, and Arran mustard soup and homemade macaroni and cheese.
Flavourful, satisfying food at very reasonable prices.
At the back of the pub, on the waterfront, is the full restaurant A Room in Leith, which, if it is anything like the Teuchters pub menu, is probably well worth the visit, too.