Rinse the quinoa in a fine-mesh sieve under cold water for 30 seconds to remove any bitterness. Combine the quinoa and 1 1/2 cups water in a small saucepan, bring to a gentle boil, then lower the heat, cover and simmer until the water is absorbed, about 15–18 minutes. Remove from the heat and keep covered for 8–10 minutes, then fluff with a fork and set aside while you prepare the other components.
Preheat the oven to 425°F. Spread the drained, dried chickpeas in a mixing bowl and toss with 2 teaspoons olive oil, 1 teaspoon lemon juice, smoked paprika, oregano, salt and pepper. Work the spices into the chickpeas with your hands so they’re evenly coated.
Arrange the chickpeas on a rimmed baking sheet in a single layer (line with parchment if you like for easier cleanup). Roast in the oven until the chickpeas are golden and crisp, about 22–24 minutes, shaking or tossing every 8 minutes so they brown evenly. Remove from oven and let cool slightly — they will crisp further as they rest.
While the chickpeas roast, whisk together the vinaigrette: 2 tablespoons olive oil, 2 tablespoons lemon juice, lemon zest, 1/4 teaspoon salt, 1/8 teaspoon pepper and a pinch of dried oregano. Taste and adjust acidity or salt as needed.
Toss the greens, cucumber, tomatoes and red onion lightly with a tablespoon of the vinaigrette to keep them bright. Reserve the rest of the dressing for finishing the bowls.
To assemble four bowls: divide about 1/2 cup cooked quinoa among bowls, then add 1 cup dressed greens, 1/4 cup cucumber, 1/4 cup tomatoes and 2 tablespoons onion to each. Scatter 2 tablespoons crumbled feta and 1 tablespoon kalamata olives per bowl.
Top each bowl with an equal portion of the roasted chickpeas, a generous spoonful of hummus, a light drizzle of tzatziki and the remaining lemon vinaigrette. Finish with chopped parsley and serve immediately while the chickpeas are still slightly warm.