Makes:1 chicken thigh, 1 chicken drumstick, 1/4 cup juices, and about 4 ounces fries each
Bake:35 mins 400°
Arrange one oven rack towards top of oven and another rack in the center. Preheat oven to 400 degrees F. Sprinkle chicken with 1/4 teaspoon of the salt and 1/4 teaspoon of the pepper; spread with mustard. Coat an extra-large ovengoing skillet with cooking spray; heat skillet over medium-high heat. Add chicken pieces, meaty sides down. Cook for 3 to 5 minutes or until brown. Remove from heat. Turn chicken pieces. Add shallots, wine, broth, and thyme sprigs. Place skillet on center oven rack. Bake, uncovered, for 10 minutes.
Meanwhile, coat a 15x10x1-inch baking pan with cooking spray; set aside. For fries, cut potatoes lengthwise into 3/8-inch-thick strips. Place russet potatoes and sweet potatoes in separate medium bowls. Add 2 teaspoons of the oil to each bowl; toss to coat. Transfer russet potatoes to the prepared baking pan; place pan on top oven rack. Bake chicken and potatoes, uncovered, for 5 minutes.
Add sweet potatoes to the pan with russet potatoes. Bake chicken and potatoes, uncovered, about 20 minutes more or until chicken is no longer pink (180 degrees F) and potatoes are just tender, turning potatoes once halfway through baking.
Remove chicken and shallots from skillet, reserving cooking juices. Cover chicken and shallots and keep warm. Transfer fries to a large bowl. Add chives, snipped thyme, the remaining 1/4 teaspoon salt, and the remaining 1/4 teaspoon pepper; toss to coat.
Bring cooking juices to boiling over medium heat. Boil gently, uncovered, for 3 to 5 minutes or until juices are slightly reduced. Remove thyme sprigs. Spoon some of the cooking juices over chicken and shallots. Serve with fries.