Preheat oven to 400 degrees. Line a baking sheet with foil or a silicone mat and place a wire rack on top.
Remove chicken from marinade and shake off any excess. Reserve extra marinade.
Place chicken skin-side down on wire rack and bake for 25 minutes.
Remove from oven and increase temperature to 425 degrees. Carefully flip chicken over, being careful not to tear the skin.
Baste with extra marinade and put some of the onion on top of each chicken leg. Season lightly with salt and pepper.
Return chicken to oven and bake another 20 minutes or until a meat thermometer reaches 165 degrees. Chicken skin should be crispy and brown, but if it is not browned to your liking you can set under the broiler for a couple minutes.