Step 1

Arrange an oven rack in the middle position. Preheat the oven to 450 degrees F.

Step 2

To make the dressing, in a large measuring cup, whisk together the garlic, white wine vinegar, lemon juice, and sumac. Drizzle in the olive oil while whisking continuously to emulsify. Season to taste with salt and pepper. Set aside.

Step 3

Toss the pita with the olive oil, a pinch of salt, and a few turns of pepper and spread out on a rimmed sheet pan. Toast in the oven until browned and toasty; Begin checking for doneness at 5 minutes. Let cool slightly.

Step 4

In a large bowl, gently toss together the lettuce, cucumbers, radishes, scallions, avocados, onions, pita croutons, chicken, and herbs, and dress to taste. Sprinkle with a little flaky salt if desired and enjoy.