Ingredients

• 4 chicken legs (thigh and drumstick; about 3 pounds)
• 1 1/2 teaspoons kosher salt, divided
• 1/2 teaspoon freshly ground black pepper
• 1/4 cup plus 1 teaspoon country-style Dijon mustard
• 3 tablespoons vegetable oil
• 2 pink-skinned apples, cut into 1/2" wedges
• 1/2 medium red onion, cut into 1/2" wedges
• 1 cup dry white wine
• 1 1/2 cups fresh apple cider, divided
• 1 large or 2 small bunches curly kale (about 1 pound), stemmed, torn into pieces
• 1/4 cup heavy cream
• 1 teaspoon fresh lemon juice
• 3 tablespoons tarragon leaves (optional)

Instructions

1. Arrange rack in upper third of oven; preheat to 450°F. Season chicken all over with 1 tsp. salt and 1/2 tsp. pepper, then rub with 1/4 cup mustard, making sure to get mustard under skin.
2. Heat 2 Tbsp. oil in a large heatproof high-sided skillet or heavy braising pan over medium-high. Sear chicken, skin side down, until golden-brown, about 8 minutes. Turn chicken, then arrange apples and onion around chicken. Add wine and 1 cup cider, then transfer to oven and roast until an instant-read thermometer inserted into thickest part of thigh registers 165°F, about 20 minutes.
3. Meanwhile, heat remaining 1/2 cup cider, 1 Tbsp. oil, and 1/2 tsp. salt in a large pot over medium; add kale, cover, and cook until wilted. Continue to cook, stirring occasionally, until kale is tender, about 5 minutes. Using slotted spoon, divide kale among plates.
4. Transfer chicken, apples, and onion to plates with a slotted spoon. Heat remaining liquid in skillet over high. Add cream and remaining 1 tsp. mustard and bring to a boil. Cook, whisking constantly, until sauce is thickened, about 5 minutes. Remove from heat and stir in lemon juice.
5. Spoon sauce alongside chicken and kale. Garnish with tarragon, if desired.