A 23 yo presents with severe abdominal pain and bloating. A 16-cm solid-appearing left complex pelvic mass is found. She has exploratory laparotomy with left salpingo-oophorectomy, pelvic and para-aortic lymphadenectomy and partial omentectomy as well as peritoneal biopsies and pelvic washings. Final pathology shows grade I immature teratoma in left ovary. All other specimens are benign. What is the best post-op management?