Crispy Za’atar Chicken and Cauliflower

Name: Crispy Za’atar Chicken and Cauliflower
Cuisine: Asian, Middle Eastern
Ingredients: 2 tablespoons (30ml) melted ghee or clarified butter; 3 tablespoons (23g) za’atar; 1 tablespoons (15ml) fresh lemon juice; 1½ tsp (9g) kosher salt; 1 head cauliflower, cut into florets (about 4 cups or 400g); 1 red onion, cut into 1-inch wedges; 3 garlic heads, tops trimmed; 2 lemons, halved; 2 pounds (905g) bone-in, skin-on chicken thighs (about 4 large thighs)