Was it Delywok Cabildo, Av. 930 ? It used to be Sushi ,chinese and parilla . Now they changed their name or restaurant to "Pan y Batata" so that may explain why you cannot find it.
It is not what you asked, but there is a restaurant called "One" freestyle restaurant. It is on Olazabal, one block from Cabildo. It looks like a nice place ambience wise. I have not been, but they have their prices in the window and the range is 53 - 75 depending on which day you go. If anybody has been I would be interested to hear their experience.