Smooth yogurt infused with garlic and herbs, crisp toasted grape leaves, and a chunky blend of chickpea, cucumber, hot pepper, and scallion make this salad especially appealing.
Place a large sieve over a bowl, and line it with four layers of cheesecloth. Place the yogurt in the cheesecloth, and tie cheesecloth closed with a rubber band or kitchen twine. Transfer bowl to refrigerator, and let yogurt drain 4 hours. Transfer the thickened yogurt to a bowl; stir in garlic and 1/2 cup chopped herbs. Set the herbed yogurt aside.
Place a large nonstick skillet over medium-high heat. When hot, spray skillet with cooking spray. Place 4 grape leaves in the bottom of the skillet. Cook leaves until crisp, 1 to 2 minutes. Spray leaves with cooking spray, and turn them over; cook until crisp on other side, 1 to 2 minutes. Transfer to a plate. Repeat with remaining 4 grape leaves. Set the toasted leaves aside.
In a large bowl, whisk together vinegar, olive oil, remaining tablespoon herbs, and salt. Season the vinaigrette with black pepper.
Add the cucumbers, hot pepper, chickpeas, and scallions to the bowl with the vinaigrette; toss the salad to combine.
Divide cucumber-chickpea salad and herbed yogurt among 4 serving plates. Garnish with toasted grape leaves; serve.