Preheat oven to 350F.
Cut turnips in halves or quarters if large. Slice white and green portions of onions into ½” rounds. Toss together in a baking dish.
Combine olive oil, herbs, and spices. Coat chicken in marinade on both sides. Place chicken on top of vegetables. Spread any excess skin out over the vegetables to baste them as the chicken cooks.
Bake for 40-50 minutes, or until turnips are easily pierced and chicken is crispy on top.
Serve with some green vegetables.