Quick Greek-style chicken gyros you can whip up on busy nights in just 20 minutes, these are a family favorite!
Puree all sauce ingredients in a blender or food processor (see note). Cover and chill until ready to serve. (If you have time, make this a few hours in advance or the night before so that the flavors can marinate)
Season chicken breasts with mediterranean seasoning. Cook in a large skillet or pan over medium heat 5-6 minutes on each side until cooked through. Cut into strips.
Lay pitas on a clean surface. Add lettuce (if desired, chicken, red pepper strips, and onions. Top with tzatziki sauce and feta (if desired). Fold pita over like a sandwich, or roll it into a "tunnel shape".
*Recipe update (1/22/15): Some readers have reported enjoying the sauce but wishing it were a bit thicker. If you are someone who loves thicker dressings and sauces, simply squeeze as much water as possible out of the cucumbers before you puree the sauce.