Follow these easy steps to create mouth-watering Greek Chicken Gyros:

1. Marinate the Chicken: In a bowl, combine the olive oil, lemon juice, garlic, oregano, salt, and pepper. Add the chicken thighs and coat them well. Cover and marinate in the refrigerator for at least 30 minutes.
2. Prepare the Tzatziki Sauce: In another bowl, combine the diced cucumber, Greek yogurt, fresh dill, and lemon juice. Mix well. Season with salt to taste and refrigerate until ready to serve.
3. Cook the Chicken: Remove the chicken from the marinade and cook it on a grill or in a skillet over medium-high heat for 10-15 minutes. Cook until the internal temperature reaches 165°F (75°C), flipping halfway through.
4. Slice the Chicken: Once cooked, allow it to rest for a few minutes before slicing it into strips.
5. Warm the Pita: Lightly toast the pita breads in a dry skillet or oven until warm and slightly charred.
6. Assemble the Gyros: Place a few strips of chicken on each warmed pita. Top with tzatziki sauce, sliced tomatoes, red onions, and lettuce if desired.
7. Add Toppings: Sprinkle some crumbled feta cheese on top for an added punch of flavor.

Enjoy the freshly made Greek Chicken Gyros!