I only ate at Cucumbertime once, but since it remains unreviewed on Yelp, I'm going to give it a…read morebump. As heads up, there are quite a few reviews on Happy Cow about this place that can offer more insight.
Komkommertijd has a nice set up for a buffet-style place, instead a little courtyard that feels very natural and peaceful. After marching all over Ghent for the day and searching for a magic unicorn of a restaurant that served both waterzooi and good vegetarian/vegan options - FYI, that didn't exist in 2009 and maybe still doesn't, we parted ways with our waterzooi-seeking companion and returned to this vegan AYCE buffet.
There was a selection of soups, app, and mains that satisfied me, including some curry and lentil dishes I liked. At 12.50 euros it was steep with the conversion rate at the time but worth it for this famished herbivore.
We were there during the second ever week of Donderdag - Veggiedag, which is something that's been in my profile photos since I joined Yelp (pause while you look through my photos). http://www.donderdagveggiedag.be/
What's a Veggiedag or veggie day? It's like a Meatless Monday, but the City of Ghent officially declared Thursday to be veggie day in 2009 and sponsored some great promotions to encourage schools and businesses to adopt healthier and environmentally-friendly eating habits. We thought this was so excellent and very progressive, so we made a weekend trip from NL, just to explore the veg offerings.
Sadly there was no big Veggie Pride Parade with dancing broccoli on Veggie Dag (they should mandate that part of the weekly event) but I did fill the hole in my artichoke heart left by the lack of visible celebration.
Whether it's Thursday - Veggie Day or not, you should check out Cucumbertime and enjoy a healthy, tasty lunch or dinner meal. Hey, maybe they have a vegan waterzooi now too?