Fluff & Chill : Cook quinoa if needed. Spread on a tray to steam-dry, then chill until barely warm. Fluff with a fork.
Burst the Tomatoes : Heat oven to 425°F (220°C). Toss tomatoes with about ½ teaspoon of the oil. Roast 10–12 minutes until skins blister. Cool.
Quick Desalting : Place feta crumbles and sliced olives in a strainer; rinse under cool water for 10–15 seconds to remove surface brine. Pat very dry.
Crisp the Chickpeas : Air fryer or skillet at 400°F (205°C). Toss chickpeas with about ½ teaspoon oil, oregano, cumin, paprika, and pepper. Cook 8–10 minutes, shaking once, until crisp. Cool.
Toast the Nuts : Dry-toast pine nuts over medium heat 2–3 minutes until golden. Transfer to a plate to cool.
Shake the Vinaigrette : Add the remaining olive oil to a jar with lemon juice, vinegar, garlic, oregano, sumac, and pepper. Shake until emulsified.
Build & Finish : In a large bowl, combine quinoa, arugula, cucumber, red onion, herbs, and roasted tomatoes. Add about three-quarters of the vinaigrette and fold gently. Scatter feta, olives, pine nuts, and chickpeas on top. Drizzle with the remaining vinaigrette and serve.