A quick search on foursquare brought this place to my attention, listed as a completely gluten-free restaurant I had to check it out.
I visited for lunch as part of a large group, so we got a good sample of the menu, the gluten-free burgers were pretty good but the buns were quite tough.
I'd actually already eaten before visiting here so opted to share the cheeseboard, only there were no crackers... just cheese. Rather bizarrely there were about 4 big chunks of butter on the plate too. Initially I thought it was a cream cheese so took a big bite. Nope. Butter.
Overall the place was OK, I visited a couple of times over the course of my time in Budapest and both times the service was a tad slow, even when the place was quiet. It's a good spot for 100% gluten-free food though.