Cook the quinoa: Transfer the quinoa to a fine-mesh strainer. Run cold water over the quinoa until the water runs clear. Transfer the quinoa to a medium saucepan with 1 ¾ cups water. Bring to a boil before reducing the heat. Cover and simmer for 15 minutes. Remove from the heat and let sit covered for 5 to 10 minutes. Fluff with a fork. Transfer to a large rimmed sheet and spread to cool.
Roast the chickpeas (optional): Preheat the oven to 425ºF. Place the chickpeas onto a large rimmed sheet. Toss with a drizzle of olive oil, paprika, cayenne, and garlic powder. Roast for about 15 minutes, or until golden brown. Set aside to cool.
Make the dressing: Whisk the olive oil, garlic, lemon zest, and lemon juice in a small bowl. Grate or press the garlic into the bowl. Season with salt and pepper to taste.
Combine the ingredients: In a large bowl, mix the quinoa, chickpeas, cucumber, tomatoes, olives, parsley, mint, green onion, and dressing.
