In a small bowl, combine cornstarch, orange juice, soy sauce, garlic and ginger until smooth; set aside. , In a large skillet or wok, stir-fry pork in oil until lightly browned, about 5 minutes; drain. Add onion, peas and red pepper; cook and stir until crisp-tender, 3-5 minutes., Stir orange juice mixture and add pan. Bring to a boil; cook and stir until thickened, about 2 minutes. Serve with rice. Garnish with green onion and sesame seeds, if desired.