Place the mixed greens in a large salad bowl.
Add quinoa, grilled chicken, chickpeas, cherry tomatoes, and red onion on top.
In a small bowl, whisk together olive oil, lemon juice, salt, and pepper.
Pour the dressing over the salad and toss gently until everything is coated.
Top with fresh parsley or cilantro if desired.
Serve immediately or store in the fridge for up to 2 days.