To create Mediterranean Chicken Gyros with Creamy Feta Tzatziki, follow these steps:

1. Prepare the Chicken Marinade: In a bowl, mix olive oil, lemon juice, minced garlic, oregano, cumin, salt, and pepper. Add chicken thighs and coat thoroughly. Cover and let it marinate for 20 minutes.

2. Cook the Chicken: Heat a grill pan over medium-high heat. Remove the chicken from the marinade and cook for 6-7 minutes per side or until fully cooked and internal temperature reaches 165°F (75°C). Remove from heat and let rest for a few minutes.

3. Make the Creamy Feta Tzatziki: In a mixing bowl, combine Greek yogurt, crumbled feta cheese, grated cucumber, lemon juice, dill, salt, and pepper. Stir until well blended. Adjust seasoning if necessary.

4. Prepare the Pita Bread: While the chicken is cooking, warm the pita bread in a skillet for a few minutes on each side until soft. Alternatively, you can wrap them in foil and heat them in the oven.

5. Slice the Chicken: Once the chicken has rested, slice it into strips.

6. Assemble the Gyros: Take a warmed pita bread and lay down the chicken slices. Top with shredded lettuce, halved cherry tomatoes, sliced red onion, and a generous drizzle of creamy feta tzatziki.

7. Garnish (Optional): For added flavor, drizzle with a little olive oil and sprinkle with fresh herbs if desired.

8. Serve: Wrap the pita around the fillings and enjoy immediately while warm!