Wow were these good (albeit a bit messy). I used Trader Joe's Cilantro chive yogurt dip instead of tzatziki. I would make the burgers a bit thinner next time so they fit into the pita without breaking them. The flavor is wonderful! I also sliced some thin red onions. This can also be made in advance and shaped so it's super easy for a backyard dinner with company. Have lots of napkins on hand they are bit messy but worth it!I served a couple of TJ's Middle Eastern salads on the side for a quick week night dinner (Tabbouli and Balela chick pea salad). I'll be making this again!