In a blender, combine tahini, lemon juice, lemon zest, vinegar, water, garlic, honey, and salt; puree and set aside.

Heat grill or grill pan to medium-high heat. Season the chicken with olive oil, salt, and pepper. Place chicken on grill and cook, without flipping, for 4-5 minutes on the first side. Flip and then cook for another 4 minutes on the second side. Allow the chicken to rest for 3-4 minutes, then slice.

In a medium bowl, combine the cucumber, grapes, scallions, feta, and chickpeas; add 1/3 cup salad dressing and toss to combine.

To serve: Portion 1/4 cup hummus on four separate serving plates and place four romaine leaves in the hummus. Top with the cucumber-grape salad mixture and sliced chicken and serve with a triangle of pita bread. Remaining dressing may be used as a dipping sauce for the bread.