A year ago a local restaurant came to our farmer's market and sold borek, (they might have called it boreg) a meat/onion mix rolled up in hand-made phyllo dough.
It was very good, but the dipping sauce that came with it was dynamite, and I can't find anything that sounds like it when I google (and the restaurant, the Euro, doesn't list borek on their menu.)
The sauce was clearly dairy based, but had an additional sharpness. Might even have been yogurt and mayo mixed with something else. Had a bit of a yellow cast. Was the texture and thickness of sour cream. Was definitely not just yogurt, which is what seems to be what's listed when I search for "dairy sauce for borek."
I don't have any idea whether it was the chef's recipe, or if it's traditional somewhere. Any ideas?