Chicken Gyros

I got this recipe here. Big E declared that the chicken "was the best chicken I've ever had!" and the last two times we've had this, that's almost all he's eaten.  

Ingredients:

Tzatziki sauce:
1 cup plain Greek yogurt

1 regular cucumber, peeled and seeded
1 teaspoon minced garlic
1 teaspoon white wine vinegar
Salt and pepper
Squeeze of fresh lemon juice
Extra virgin olive oil

For the chicken:
2 teaspoons minced garlic
Juice of 1 lemon (2-3 Tablespoons)
2 teaspoons red wine vinegar
2 Tablespoons extra virgin olive oil
2 heaping Tablespoons plain Greek yogurt
1 Tablespoon dried oregano
Salt and pepper
1 1/4 lbs. boneless, skinless chicken breasts

To assemble: Pita bread
Fresh tomatoes, seeded and diced
Red onion, sliced thin

Instructions:
Shred the cucumber or chop in food processor. Wrap in a towel a squeeze to remove as much water as possible. Mix together the yogurt, shredded cucumber, garlic, white wine vinegar, salt and pepper to taste, and lemon juice. Drizzle lightly with olive oil.

Refrigerate for at least 30 minutes before serving to allow the flavors to meld.

To prepare the chicken, combine the garlic, lemon juice, red wine vinegar, olive oil, yogurt, oregano, and salt and pepper to taste in a medium bowl. Whisk together until mixed well. Add the chicken pieces to the bowl and mix well to coat. Cover and refrigerate for about 1 hour.

Cook the chicken as desired, either in the skillet or with the broiler. Once the chicken is completely cooked through, transfer to a plate and let rest for 5 minutes. Cut into strips. Heat pitas. Top with chicken, tzatziki sauce, diced tomatoes and sliced onions. Serve immediately.