I had been really surprised that Cat Ba had a vegan option, but my excitement was quickly gone. Where should I start? Probably with the fact that this place has the worst service I've ever encountered. First time we arrived there around 2pm, to find the place open, but no one willing to serve us, with one person sleeping in the back. So we'd given it a second chance and arrived later in the evening. We were given the menus by one person, while the order was taken by a random woman who just arrived. Weird. We ordered 3 meals - two of them were supposed to come with a soup that never arrived, third one simply never showed up. After finishing the food, no one was willing to take the payment from us, as there simply was no one around. No one. We sat there for additional 30 minutes, left the money on the table and left the place. I don't expect the service to be like from a 5-star hotel, but I'm a polite person myself and expect this from others. Mutual respect is the key, especially when you choose to eat food prepared by the other person. Worst service ever.
The food itself? Bland. We were served a stew with veggies and some fake meat that was simply okay. Nothing too exciting. I just wished the rice wasn't dry, as it seemed like it had been cooked a day earlier.
I suggest avoiding this place and trying veggie/vegan options with other places on the island, as they're much better and people are nice and grateful.

My friend and I both ordered vegetable noodle soup, that tasted real good. However, we found three maggots in our meal. We optimistically assumed it is from the greens or vegetables in the soup, and removed them from our food. However, later on both of us got stomach aches. So be careful eating there.

Went there for lunch and couldn't find the place.