• ¼ cup olive oil, divided
• 1.50 tablespoons shawarma seasoning, such as McCormick
• 1.50 pounds boneless, skinless chicken thighs (about 5 total)
• 1 red onion, cut into ½-in. wedges
• ¾ cup (6 oz.) plain whole-milk Greek yogurt
• ¼ cup chopped mint and/or parsley, plus leaves for serving
• 3 tablespoons fresh lemon juice (from 2 lemons)
• ¾ teaspoon kosher salt, divided
• 1 5-oz. container baby arugula
• 2 cups grape tomatoes (about 10 oz.), halved
• 2 6-in. pita rounds, quartered

Preheat broiler with rack 6 inches from heat. Stir together 2 tablespoons oil and seasoning in a large bowl. Add chicken and toss to coat. Toss onion wedges with 1 tablespoon oil on a large, rimmed baking sheet lined with foil. Arrange onion wedges along outer edges of baking sheet. Place chicken in center of baking sheet. Broil until onions are charred in spots and crisp-tender and chicken is cooked through, 12 to 15 minutes.

Meanwhile, whisk yogurt, herbs, lemon juice, ¼ teaspoon salt, and remaining 1 tablespoon oil in a small bowl. Whisk in 1 to 3 tablespoons water as needed to reach drizzling consistency. Remove baking sheet from oven and let chicken rest for 5 minutes. Transfer to a cutting board and thinly slice. Sprinkle with remaining ½ teaspoon salt. Top arugula with tomatoes, sliced chicken, and onion wedges. Drizzle with yogurt dressing and top with herbs. Serve with pita.