01 - Preheat oven to 425°F. Line a large sheet pan with parchment paper.
02 - In a large bowl, combine chicken strips, bell peppers, onion, olive oil, paprika, oregano, garlic powder, salt, and pepper. Toss until evenly coated.
03 - Spread mixture evenly on prepared sheet pan. Bake for 20-25 minutes, tossing halfway through, until chicken is cooked through and vegetables are tender and slightly caramelized.
04 - While chicken cooks, whisk together Greek yogurt, mayonnaise, buttermilk, garlic, parsley, dill, chives, lemon juice, salt, and pepper until smooth. Adjust seasoning to taste.
05 - Wrap pita breads in foil and warm in oven during the last 5 minutes of baking.
06 - Fill each pita with roasted chicken and vegetables. Top with cherry tomatoes, cucumber, generous drizzle of herby ranch, and feta if using. Garnish with extra herbs and serve immediately.