Preheat the oven to 450°F (230°C). Position one rack in the center and another beneath the broiler.
In a medium bowl, whisk together olive oil, lemon zest, lemon juice, garlic, oregano, salt, and pepper.
Add the chicken thighs and toss until evenly coated. Marinate for 30 minutes at room temperature or refrigerate for up to 6 hours.
Line a baking sheet with foil if desired. Arrange the sliced potatoes on the sheet.
Drizzle the potatoes with olive oil and half the lemon juice. Add oregano, smoked paprika, garlic powder, salt, and pepper. Toss well and spread into a single layer.
Roast the fries for 20 minutes. Flip them and continue roasting for another 10–15 minutes until golden and crisp.
Squeeze the remaining lemon juice over the fries immediately after roasting.
Place the marinated chicken on a separate baking sheet.
When the fries are flipped, place the chicken in the oven and roast for 10–15 minutes until fully cooked.
Remove the chicken and slice into bite-sized pieces.
For extra texture, return the sliced chicken to the baking sheet and broil for 4–5 minutes until lightly browned and crisp.
To prepare the yogurt drizzle, whisk together Greek yogurt, lemon zest, lemon juice, garlic, dill, salt, and pepper.
Add water as needed to achieve a smooth drizzling consistency.
Warm the pita bread for 1–2 minutes.
Assemble the Lemony Greek Chicken Pitas by filling warm pita bread with lettuce, fries, chicken, cucumber, feta, pickled onions, and a generous drizzle of yogurt sauce.
Serve immediately and enjoy