Dosei (.
Google
The food was great, the service staff were quick and welcoming, and the atmosphere was nice. The portion sizes are quite big, but you can take the leftovers with you, which is super nice.
It is a bit expensive in terms of polish standards, but you get what you pay for and more. I can especially recommend their bigos and borsch, they are both excellent.
The only negative i have is that the door creates a cold draft whenever it is opened.