This is a simple recipe that puts za'atar, the beloved Lebanese spice blend of wild thyme, sumac, and toasted sesame seeds, in a starring role in a garlicky, lemony marinade.
In a large bowl, whisk to combine the garlic, salt, lemon juice, 2 tablespoons of the za’atar and olive oil. Add the raw chicken pieces and turn them to coat completely. Cover and refrigerate for at least 2 hours and up to 12 hours.
When the chicken is ready, arrange an oven rack in the middle position and preheat the oven to 425°F. Line a large baking sheet with non-stick foil.
Peel and cut the potatoes into 1-inch thick disks. Peel and cut the carrots on the bias in 1-inch pieces.
In a mixing bowl, add the potatoes, carrots, olive oil, salt, and garlic powder. Stir until well-coated.
Arrange the marinated chicken pieces skin side up, potatoes, and carrots on the prepared baking sheet.
Bake until the chicken reaches an internal temperature of 175°F on an instant read thermometer and the skin is deep golden brown, and the vegetables are golden, 1 hour. When the chicken has baked for 45 minutes, remove the pan from the oven and baste the chicken with the juices, then carefully spoon off or use a bulb baster to remove several tablespoons of the liquid. Return the pan to the oven to continue baking for 15 minutes longer, until the chicken is golden brown.
Remove from the oven, place the chicken on a serving platter, and dust with 2 tablespoons za’atar.