Pan Roasted Chicken with Za’atar, Potatoes, and Greens

4 teaspoons Za’atar
1/4 cup olive oil plus more for drizzling
Kosher salt and freshly ground pepper
3 pounds bone-in, skin-on chicken thighs and drumsticks
1 pound fingerling potatoes cut in half lengthwise
1 medium red onion, peeled, halved, and cut into 1/2 inch wedges
1 lemon cut in half
1 bunch (8 ounces) kale, ribs removed, torn into 2-inch pieces (about 4 cups)

• Preheat oven to 425 degrees, with racks in upper and lower thirds. In a small bowl, mix Za’atar with 2 tablespoons oil and 2 teaspoons salt.
• With a sharp knife, cut two 1-inch long slashes in each piece of chicken, through skin and down to bone. Rub Za’atar all over chicken and into slashes.
• On a rimmed baking sheet, toss potatoes with 1 tablespoon oil; season with salt an pepper. Roast in lower third of oven, stirring once, until starting to brown, about 20 minutes. Toss onion with remaining 1 tablespoon oil season with salt and pepper; add to baking sheet along with chicken pieces and lemon halves. Roast until a thermometer inserted into thickest part of chicken (not touching bones) registers about 150 degrees. 25 to 30 minutes.
• Switch oven to broiler setting. Moving baking sheet to upper third of oven: broil until chicken is browned, 2 to 3 minutes. Drizzle kale lightly with oil; season with salt and pepper. Scatter kale over chicken and broil until just wilted and thermometer inserted into chicken registers 165 degrees. 1 to 2 minutes more. Let cool slightly then squeeze lemon halves over chicken. Remove chicken to a platter; toss vegetables together and serve alongside.
• Baby kale, spinach, or arugula can be used in place of the kale.