Step 1: Marinate the Chicken

1. In a bowl, whisk together olive oil, lemon juice, garlic, oregano, paprika, cumin, coriander, salt, and pepper.
2. Add the chicken and coat it well with the marinade. Cover and refrigerate for at least 2 hours (or overnight for maximum flavor).

Step 2: Prepare the Tzatziki Sauce

1. Grate the cucumber and squeeze out excess water using a clean towel.
2. In a bowl, combine Greek yogurt, cucumber, garlic, dill, olive oil, lemon juice, and salt. Mix well and refrigerate until ready to serve.

Step 3: Cook the Chicken

1. Heat a skillet or grill pan over medium-high heat.
2. Add the marinated chicken and cook for 4-5 minutes on each side until golden brown and cooked through (internal temperature should reach 165°F).
3. Let the chicken rest for 5 minutes, then slice it into thin strips.

Step 4: Warm the Pita Bread

1. Heat the pita bread in a dry skillet for 30 seconds on each side or wrap them in foil and warm in the oven.

Step 5: Assemble the Gyros

1. Spread a generous layer of tzatziki sauce on each pita.
2. Add sliced chicken, lettuce, tomatoes, red onion, feta cheese, and any additional toppings you like.
3. Fold the pita into a wrap and serve immediately.