Sumac chicken with Cauliflower and Carrots

6 tablespoons olive oil, divided
1 tablespoon sumac
1 ¼ teaspoon kosher salt, divided
1 teaspoon light brown sugar
1 teaspoon Spanish paprika
¼ teaspoon ground red pepper
1 lb. cauliflower florets
2 ( 6oz.) small rainbow carrots, halved lengthwise
1 lb. chicken drumsticks, skinned
1lb. bone- in chicken thighs ,skinned
1 lemon halved lengthwise(save ½ for juice and thinly slice the other ½)
1 small red onion cut into ¾ inch wedges
½ cup finely chopped fresh flat leaf parsley
½ cup chopped fresh cilantro
1 tablespoon fresh lemon juice
1 clove garlic, minced

• Preheat oven to 425 and line rimmed sheet pan with foil or parchment paper.
• Combine 3 tablespoons oil , sumac, 1 teaspoon salt, brown sugar, paprika and red pepper in a medium bowl. Place cauliflower and carrots on the baking sheet. Pour half the oil mixture over vegetables, toss to coat. Add the chicken thighs, drumsticks and lemon slices to the pan. Rub remaining oil mixture over chicken. Bake 425 degrees for 20 minutes.
• Stir vegetables and sprinkle onion wedges over pan. Bake for another 20 minutes or until chicken is done and internal temperature reaches 165 degrees.
• Combine remaining 3 tablespoons oil, ¼ teaspoon salt, parsley and remaining ingredients in a small bowl. Spoon parsley mixture evenly over chicken and vegetables and serve.