Slice onion thin and place in large roasting pan, slice potatoes in half and add to onion. Mix sauce, oil, wine, garlic and spices and drizzle 2 Tbsp over onions and potatoes. Stir to coat, then push vegetables to the sides of the pan.
Rinse chicken in cool water and pat dry with paper towels. Place chicken pieces in the center of the roasting pan and brush with sauce. Flip each piece over and coat well, then turn face up and pour the remainder of the sauce over top. Roast uncovered at 350 degrees for 2 hours, basting with marinade every 30 minutes