Preheat your oven to 425°F (220°C).
In a bowl, whisk together all Herby Ranch ingredients and refrigerate.
On a sheet pan, combine chicken, peppers, and onion.
Drizzle with olive oil and add all seasonings. Toss well.
Spread evenly and roast for 20–25 minutes, flipping halfway.
Warm the pitas.
Fill each pita with lettuce, roasted chicken and vegetables, tomatoes, and drizzle generously with herby ranch.
This Sheet Pan Chicken Pitas with Herby Ranch recipe is best served warm and fresh.