How to Make It
Preheat oven to 425°F.
Combine 3 tablespoons oil with sumac, 1 teaspoon salt, brown sugar, paprika, and red pepper in a medium bowl. Place cauliflower and carrots on a foil-lined baking sheet. Add half of oil mixture; toss to coat. Add chicken thighs, drumsticks, and lemon slices to pan. Rub remaining oil mixture over chicken. Bake at 425°F for 20 minutes. Stir vegetables. Sprinkle onion wedges over pan. Bake at 425°F for 20 more minutes or until chicken is done.
Combine remaining 3 tablespoons oil, parsley, and remaining ingredients in a small bowl. Spoon parsley mixture evenly over chicken and vegetables.