Combine all ingredients except sliced onion and chicken into the bowl of a food processor and mix well.
Cover the bottom of a shallow baking dish with a small amount of the sauce. Place chicken in the dish, skin side down, and cover with 1/2 of the remaining sauce.
Place a aluminum foil tent over the pan.
Place in a pre-heated 350 degree oven and bake for 20 minutes. Turn the chicken over and bake 20 minutes longer.
Remove the aluminum foil tent. Place onion slices on chicken and baste with the remaining sauce.
Raise the oven temperature to 400 degrees, or place under broiler for 5-10 minutes for glaze to form. Remove from oven and let the chicken rest for 5 minutes. Serve and enjoy!