These burgers are so tasty! I was looking for something different and I found it! I followed the recipe as written. I used regular yellow mustard and store-bought pita. Of course I didn't have the kaymak and ajvar - didn't even know what it was. This was so good and different that now I'm very interested in Serbian cuisine. I found a lot of information on Wikipedia and recipes for kaymak and ajvar on the internet. I'll try to make those next time. JUST GOOD!!!