Spiced Chicken Kebabs with Pita

Name: Spiced Chicken Kebabs with Pita
Ingredients: 1 clove garlic, minced; Kosher salt and freshly ground pepper; ½ cup 5 percent-fat Greek yogurt; 1 pound boneless, skinless chicken breasts or thighs, cut into 1 ½-inch pieces; 1 orange bell pepper, seeded and cut into 1-inch pieces; ½ large red onion, cut into 6 wedges with root end intact; 2 tablespoons extra-virgin olive oil, plus more for drizzling; 2 teaspoons za'atar, plus more for sprinkling; 6 pitas (each 6 inches); 2 mini cucumbers, halved lengthwise and chopped; ½ cup fresh mint leaves