If not already cooked, prepare quinoa according to package instructions.

Grill chicken breast until fully cooked, then slice it into strips or bite-sized pieces.

In a large bowl, combine the cooked quinoa, sliced chicken, rinsed chickpeas, diced cucumber, halved cherry tomatoes, pitted olives, crumbled feta cheese, and mixed greens.

For the dressing, whisk together tahini, lemon juice, water, garlic powder, salt, and black pepper in a small bowl until smooth.

Drizzle the tahini dressing over the assembled bowl. Serve immediately.