Drizzle the remaining olive oil around the pan. Add the orange zest, onion, and red pepper, and cook, stirring until slightly tender, about 3 minutes. Rewhisk the sauce, pour into the pan, and stir to coat the vegetables. Bring to a boil and cook until thickened, about 1 minute. Return the beef to the pan and stir to combine. Serve over rice and top with scallions. Enjoy!