In a medium saucepan bring 1½ cups water and the quinoa to boiling; reduce heat. Simmer, covered, 15 minutes or until water is absorbed. Spread quinoa on a large baking sheet to cool.
Meanwhile, for dressing, in a small bowl whisk together lemon zest and juice, feta, olive oil, oregano, and 1 tsp. salt.
In a medium bowl combine the cooled quinoa and half of the dressing. Spread spinach on a platter. Spoon quinoa mixture over top. Arrange chickpeas, bell peppers, cucumber, and olives on platter. Drizzle remaining dressing over all and sprinkle with red onion. Top with pita chips. If you like, drizzle with additional olive oil.
