Mix all the ingredients together in a bowl.
Place them in the refrigerator while you make the burgers.
Using a large mixing bowl, gently blend the first eight ingredients by hand.
Form the mix into four equal-sized burgers. If you are having trouble getting the burgers to stick together, you can add an egg.
Refrigerate.
Set up your grill for medium-hot heat.
Spray the grates, so your burgers don’t stick.
Grill the burgers for about 4 minutes per side. You don’t want them going over medium rare, or they’ll be dry (120F internally).
Brush the pita lightly with olive oil and sprinkle with greek spices.
Wrap in aluminum foil and warm on the grill while the burgers rest for 5-10 minutes.
Assemble with lettuce and tomato inside the pita, offering the Tzatziki as a dipping sauce.