Cut the chicken and soak in the marinade for 15 minutes. Heat a wok and add 2 T of the oil. Drain the marinade from the chicken and reserve. Brown the chicken pieces well in the wok, then remove and set aside. Drain the oil from the wok and discard. Heat the wok again and add the remaining 2 T oil. Chow the garlic for a moment and add the onions and the dow see mashed with the sherry. Chow for a moment and add the green peppers. Return the chicken to the wok along with the reserved marinade. Add the ingredients for the final sauce. Stir well and cover. Simmer the dish until the chicken is tender but not overcooked, about 20 minutes.