Lemon Tahini Dressing: Whisk together yogurt, tahini, lemon juice, water, garlic, salt and pepper.
Cook pasta according to package directions. Drain and rinse under cold water; transfer to large bowl.
Add arugula, tomatoes, chickpeas, cucumber, Kalamata olives, red onion, half of the parsley and half of the feta to pasta; drizzle with dressing and toss to coat. Sprinkle with remaining parsley and feta cheese. Serve immediately.