Komsu Kafe

I went there on one of their themed evenings. It was really crowded! I heard it is less crowded on "normal" days though ;)
the food was very delicious but unfortunately it was not labeled so I think I acidentially ate non-vegan food as well...which really sucks.
the bufet was 15TL donation.

If you're interested in leftwing politics, this is the place for you. Not only they will get you really delicious food, but also you can be part of a place which tries to suck less than the usual commercial places in the city. You can choose your own price, no one will comment on that.

Enjoyed the food, and almost everything was vegan :)
Friendly people, lovely place with seating outdoors and indoors, including a spacious second floor with bookshelves and sofas.
You eat what you want and pay what you want.

Komsu Kafe is a community run kitchen of sorts. I don't think there is a formal structure (as even their manifesto admits) and people are free to make their own food or eat whatever is made. I went right as they were preparing lunch. Basically you just serve yourself and pay what you think is fair, although they have recommended prices should you feel uncomfortable. I had a great lunch plate with tea and they suggested 6 TKL (I ended up giving them 12).

I totally recommend this cafe should you find yourself in Kadikoy. It's about a 10 minute walk from the ferry.

This cafe does veggie sausages, which I didn't try, but were well-priced, 6 lira at time of writing. They also deliver by bicycle if you are close by.

I had some homemade tomato ravioli with salad, which although it took quite long to come, was exceptionally good. In addition to that they pressed me some fresh green apple juice. There was also a potato vegetable stew, which had an African influence from the cook, (thumbs up)! I also took some vegetarian kofte to go, which was made from red lentils and was delicious. I will definitely be back!

The location is quite easy to find, maybe less than 10 mins walk from the Kadikoy ferry.