In a food processor, blitz the chopped onion, garlic, olive oil, lemon juice, spices, salt, and oregano until smooth. If using Greek yogurt, add it at the end and pulse until combined. The onion-based mixture both flavors and tenderizes the wings.
Pat wings dry, then toss them in the marinade, rubbing it under the skin where possible. Cover the bowl or seal in a bag and chill for at least 30 minutes, ideally 2–4 hours or overnight for best infusion. Longer marinating gives deeper flavor and more tender meat.
Heat your grill to medium or medium-high and oil the grates to prevent sticking. If using charcoal, let the coals reach steady medium heat so wings cook evenly without burning. A properly heated grill helps render the skin for crispy results.
Place wings in a single layer over indirect or medium heat, turning every few minutes for even color. Cook until the skin is nicely charred and an instant-read thermometer reads at least 165°F in the thickest portion. Total grilling time can vary; allow patience for even cooking without flare ups.
Let wings rest a few minutes off the heat so juices redistribute, then transfer to a serving platter. Sprinkle with chopped parsley and an extra squeeze of lemon if you like. Serve with cooling dips like tzatziki or a simple yogurt-garlic sauce to complement the spices.