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