Prick the skin of the chicken legs in several places with the point of a sharp knife.
Put the chicken in a large non-metallic shallow pan or glass dish; Pour the marinade over the chicken.
Turn the legs several times to coat the pieces evenly; Cover tightly with plastic wrap and refrigerate over night.
Preheat the oven to 350 degrees.
Wipe off any garlic or onion pieces from the chicken legs and put them side by side in two large roasting pans - If necessary put one pan on the lower shelf and the other on the next shelf up in the oven.
Roast for 30 minutes.
Meanwhile, strain the marinade and set it aside.
After the chicken has cooked for 30 minutes, turn each piece and brush the chicken liberally with the marinade.
Rotate the pans on the shelves; Roast for 30 minutes more, or until the legs are golden brown. Turn again if necessary.