Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper.
In a large bowl, combine the diced chicken, garlic powder, paprika, cumin, olive oil, salt, and pepper. Toss until the chicken is evenly coated with the spices.
Spread the seasoned chicken on one half of the sheet pan. On the other half, arrange the sliced red and yellow bell peppers and red onion. Drizzle a little olive oil over the vegetables and season with salt and pepper.
Bake in the preheated oven for about 20-25 minutes, or until the chicken is fully cooked and the vegetables are tender and slightly caramelized.
While the chicken and vegetables are baking, prepare the herby ranch sauce. In a medium bowl, combine Greek yogurt, mayonnaise, dill, parsley, lemon juice, garlic, salt, and pepper. Mix well and set aside.
Once the chicken and vegetables are done, remove the sheet pan from the oven.
Cut the pitas in half to create pockets and fill each pocket with a generous amount of the baked chicken and veggies.
Drizzle the herby ranch sauce inside each pita and serve immediately.
Notes
Serve the filled pitas on a large platter, garnished with fresh herbs and lemon wedges for an inviting look.