Finely chop the turkey liver. Heat the olive oil in a large skillet and add the sweet potato, onion and muchrooms. Stir well. Add the turkey liver and stir again. Cover and cool about 10 minutes. Stir again and add he herbs. Cover and let cook another 10 minutes, stirring often. Remove the mixture from the skillet and allow to cool in a glass dish. When cooled to room temperature, use this stuffing to stuff the turkey. Cook the turkey according to weight.