Place the chicken in a large zip top baggie and set aside.

In a medium bowl combine the Tzatziki, olive oil, red wine vinegar, lemon juice, salt and pepper. Mix well and pour over top of the chicken in the baggie. Marinate in the refrigerator for at least 1 hour or overnight.

Combine all the ingredients for the cucumber onion salad in a small bowl. Mix well and refrigerate until ready to use.

When ready to make the gyros heat 1 tablespoon of olive oil in a large skillet over medium high heat.

Remove the chicken from the marinade and let any excess drip off. Add in the chicken breast tenders and cook for 5-6 minutes per side or until cooked through.

Remove from the pan and slice into 1 inch pieces.

To make the gyros spread 1 tablespoon of Tzatziki on each pita. Divide the chicken between the pitas and then place 1-2 tablespoons of cucumber onion salad on top. Sprinkle with feta cheese and roll up the gyro.

Serve with remaining Tzatziki Dip.