Preheat oven to 425 degrees.

Mix a tablespoon of the olive oil with the salt, pepper, onion powder and sumac in a big baking dish.

Salt and pepper the chicken inside and out to your preference.

Mix the lemon zest, rest of olive oil and zaatar in a small bowl.

Fill the inside of the chicken with the shells of the lemon, rosemary and garlic. Then coat the outside with the spice mix that had the zaatar.

Put the chicken into the baking dish and roast on 425 for 15 minutes to make a nice crusty coating. Then lower to 350 and roast for another 80 minutes.

Take out of oven and let cool. Remove the stuffing and discard.