I couldn't find much on Leeds when I searched here before my trip, so I wanted to add some ideas in case someone needs the info in the future.
I'm not a vegetarian, but the food is dependable and surprisingly good with friendly service and a great atmosphere at Fruits and Roots. It's in one of the many covered arcades in downtown Leeds. Not for vegans because they seemed to use plenty of cheese (yummm!), but their homemade desserts are out of sight. Three of us ordered the great and filling ratatouille/potato moussaka, followed by the brioche and raspberry bread pudding.
I didn't get a chance to explore too much more in Leeds, but I did have the best chips of my life in Bowness-on-Windermere, in the Lake District. Just wrote about this in another thread. I forgot what the little storefront was called, but the chips were light and crispy right down to the very last chip. A great snack while browing through the shops, and it made quite a few shopowners drool. It's in the main shopping area, not far from the docks, with a blue and white banner on the front.
Also heard good things about a restaurant called the Far Side in Ilkley, not far from Leeds, but it was closed when we were there.