If you plan to discard the chicken skin, skip poking with skewer. This recipe can be easily doubled.
Toss potatoes with 1 teaspoon oil, coriander, ¼ teaspoon salt, and ¼ teaspoon pepper in large bowl. Arrange potatoes in even layer in air-fryer basket; do not clean bowl.
Using metal skewer, poke skin side of chicken 10 to 15 times. Pat chicken dry with paper towels and sprinkle with remaining ¼ teaspoon salt and ¼ teaspoon pepper. Arrange chicken skin side up on top of potatoes, spaced evenly apart. Place basket into air fryer; set temperature to 350 degrees; and cook until potatoes are tender and chicken is well browned and crisp and registers 195 degrees, 30 to 40 minutes, tossing potatoes and rotating chicken halfway through cooking (do not flip chicken).
Transfer chicken to clean plate and discard skin, if desired. Tent with aluminum foil and let rest while finishing potatoes and salad. Return basket to air fryer and increase temperature to 400 degrees. Cook potatoes until golden brown and crisp, 6 to 10 minutes.
Whisk remaining 2 tablespoons oil, lemon juice, thyme, and mustard together in large bowl; stir in tarragon. Spoon 2 tablespoons dressing over chicken. Add mesclun, radishes, and scallions to bowl with remaining dressing and toss to coat. Season with salt and pepper to taste. Serve chicken with potatoes and salad.
