Cook's Note: To roast garlic, cut off the top third of each garlic head, drizzle with EVOO and wrap in foil. Roast in a 400 degree F oven until tender.
Squeeze the roasted garlic from the skins and combine with the softened butter, EVOO, rosemary, chile and lemon zest. Loosen the skin all over the chicken, then rub the garlic mixture onto the meat under the skin. Sprinkle the skin with salt and pepper. Put the chicken in a baking dish, cover and let stand for 1 hour.
Preheat the oven to 325 degrees F. Sprinkle the chicken with two-thirds of the Za'atar Spice Blend and roast for 1 hour 15 minutes. Raise the oven temperature to 500 degrees F and roast for 15 minutes more to crisp the skin. Let the chicken rest until cooled, then cut it into quarters.
Meanwhile, heat a griddle or grill pan and grill the naan until warm. Brush with melted butter and cut in half.
Divide the chicken quarters among plates and sprinkle with the remaining Za'atar Spice Blend and the lemon juice. Serve with the naan and Green Harissa.
Za'atar Spice Blend:
Combine the sesame seeds, sumac, thyme, cumin, oregano, salt and pepper. Store in an airtight container until ready to use. Cook's Note: The spice blend is great on chicken, beef, lamb, eggplant and anything grilled. You can make extra and store it for weeks. Sumac is available in larger markets and Middle Eastern markets.
Puree the cilantro, EVOO, cumin, chile peppers, garlic, spinach and lemon juice in a food processor until fairly smooth. Season with salt and pepper. Refrigerate or serve immediately.