Preheat grill pan over high heat. Place chicken in shallow dish and season with salt and pepper.
Preheat oven to 275 degrees F. Wrap pita breads in foil. Place in warm oven and heat until dinner is served.
Combine lemon zest, juice and vinegar in a bowl and whisk in oil. Add oregano, garlic and whisk again to combine into dressing. Pour half the dressing over chicken tenders. Turn tenders in dressing to coat.
Combine remaining salad ingredients in a bowl. Pour remaining dressing over salad and toss well. The salad should be very lightly dressed. Season salad with salt and pepper and transfer to a large serving platter.
Grill tenders 4 to 5 minutes on each side. Transfer hot tenders to the salad lined serving platter. Remove pitas from oven and unwrap. Cut pitas in half and arrange around the edge of platter.
To serve, each person can pile grilled chicken and veggies into pita halves, wrap up on either side and enjoy!