HEAT THE OIL in a large, lidded skillet and brown the chicken pieces on all sides. Add all other ingredients, bring to a boil, cover, reduce heat to low and simmer until chicken is done, about 30 minutes. Remove the chicken to a platter and set aside. Place the cooking liquid in a blender or food processor and blend until as smooth as possible. Return the sauce to the skillet, replace the chicken and cook everything together another 10 minutes. Serve with tortillas, rice, beans and tamales.