1Prepare rice according to package directions. Remove from heat and let stand, covered, until ready to serve.
2While rice is cooking, halve and squeeze 5 or 6 tangerines or 2 oranges to yield 2/3 cup of juice. In a medium bowl, whisk together juice, soy sauce, honey, and cornstarch. Set aside. Remove peel off remaining 2 tangerines or 1 orange. Cut half of peel into 1/4-inch strips (discard remaining peel). Set aside. Cut fruit into bite-sized pieces. Set aside.
3In a large wok or skillet over medium-high heat, warm oil. Add fruit peel and stir-fry for 30 seconds. Add onion and stir-fry for 30 seconds. Add pork and stir-fry until pork is cooked through and onion is crisp-tender, 3 to 4 minutes. Add juice mixture and fruit and cook, stirring occasionally, until mixture comes to a boil and thickens, about 1 minute.
4Serve stir-fry over rice sprinkled with cilantro, if desired.