From the description I was really looking forward to eating here. I wish I could give a more positive report (regarding the vegetarian aspect of the restaurant) because the waiters were very warm, friendly and apologetic for all their mistakes.
Positives: good location, easy walking distance of Termini, outdoor seating on a quiet street. The prices were reasonable and the atmosphere was nice.
However, there was almost nothing on the menu that was vegetarian, and even less that was vegan. I had a salad, which was good, but not exceptional. Then I ordered a pasta dish, being sure to check that the pasta itself was not made with eggs. My very nice waiter assured me that it was not. When it arrived I noticed immediately that the pasta was yellow, so told another waiter that I thought that the pasta was made with eggs; he replied, yes, of course. So I explained that I'd already checked this and was told otherwise. He was extremely apologetic and said he'd ask the cook to make it again with a different type of pasta. I think I had to wait at least 30 minutes, maybe more, but finally it came. It was vegan but again nothing very special.
There were a number of other mistakes which in themselves were not upsetting, but added together, made my dinner more confusing than enjoyable. I asked for aqua gassata, but got naturale. Also there was an error in the bill. Everything was corrected with many apologies, but I got the impression (from observing other diners too) that they were quite disorganised.
I'm surprised that this restaurant is on Happy Cow's list, when there are many, many non-vegetarian restaurants in Rome that have excellent vegetarian (and vegan) options. That is to say, this restaurant is no more vegetarian than any of the others.
It's unfortunate, because the staff were exceptionally pleasant.
Cons: almost no vegetarian or vegan options, staff made a lot of mistakes, food rather mediocre