Found this after after a quick search on happy cow.
The food here is excellent. Everything you would get from a traditional Mexican cafe / bistro (plus some more)- but all suitable for vegetarians. The faux meat dishes are exceptional, especially the tacos for which you can choose 6 different types of faux meats.
English is limited, but you can get by ... Especially if you have some sort of translator in the phone (the free wifi here helps for apps such as google translator)
We ate on Sunday lunch time and the place was packed with locals and tourists.
Would recommend and definitely coming back if in Mexico City.