Musakhan Chicken

4 chicken legs, split into drumsticks and thighs (about 3 pounds; 1.3 kg total)

2 pounds (907 g) small yellow medium-starch potatoes such as Yukon Gold, peeled, halved lengthwise, and cut crosswise into 1/2-inch slices

6 tablespoons (90 ml) extra-virgin olive oil

2 tablespoons sumac, plus more for serving (see notes)

2 1/4 teaspoons ground allspice

2 teaspoons ground coriander

1 1/2 teaspoons ground cinnamon

1 teaspoon ground ginger

1 teaspoon cardamom

1 teaspoon freshly ground black pepper

4 teaspoons (12 g) Diamond Crystal kosher salt, for table salt, use half as much by volume or the same. weight

2 medium yellow onions (about 16 ounces total), cut into 1/2-inch slices

1/4 cup (6 g) finely chopped fresh oregano leaves, plus more for serving

Lemon wedges, for serving

Plain whole-milk yogurt, for serving

Adjust oven rack to upper-middle position. Heat oven to 425°F (220°C). On a rimmed baking sheet, combine chicken and potatoes. Drizzle with oil and sprinkle evenly with sumac, allspice, coriander, cinnamon, ginger, cardamom, pepper, and salt. Rub all over and toss to ensure chicken and potatoes are evenly coated. Transfer chicken to a bowl or plate and spread potatoes in an even layer on baking sheet. For better salt penetration, let chicken sit at room temperature for 30 minutes or uncovered in the refrigerator for up to 8 hours, if desired.

Bake potatoes for 10 minutes. Remove rimmed baking sheet from oven, add onions, and toss gently with potatoes to combine. Return chicken to rimmed baking sheet, placing pieces along the edges of the pan, on top of potato and onion mixture for better browning. Return baking sheet to oven and cook until potatoes are almost tender and chicken is beginning to crisp. Remove pan from oven, scatter oregano on top of chicken and potatoes, return to oven, and continue to cook until potatoes are tender and chicken is golden brown and crisp, 10 to 15 minutes. Sprinkle with additional sumac and serve with lemon wedges and yogurt.