Set the quinoa to cook. Preheat the oven to 400F.
Preheat the grill to high heat to grill the peppers. ( Alternatively, you can roast these- see notes).
Cut peppers in half lengthwise and grill them on each side for about 6-7 minutes or until tender, and a little charred. (They will soften more in the oven later)
While peppers are grilling, heat oil in a large skillet and sauté the onion and eggplant over medium heat until eggplant is tender. Add the garlic and another little drizzle of oil if needed and cook 2 more minutes until garlic is fragrant. Add the chickpeas (or cooked meat) and quinoa and season generously with the zaatar spice. Taste, and add more to taste.
Season generously with salt and pepper. Add lemon zest and parsley. Taste and adjust salt and seasonings. If the mixture seems dry add a splash of water to loosen just slightly.
Place peppers in a baking dish and divide the filling among them, packing and mounding them up high. Cover with foil and bake for 25 minutes, remove foil, and bake for 10 more minutes.
Spoon the flavorful Zhoug yogurt over top, or serve on the side. Garnish with more parsley and optional pine nuts.