Directions

1. Stir together soy sauce, cornstarch and vinegar. Add sliced beef and stir to coat. Cover and refrigerate 10 minutes or up to 1 hour.
2. Make the sauce and prepare the aromatics: Zest one orange and remove the orange peel from the other one in thin strips, avoiding the white pith. Squeeze both oranges to yield 1/2 cup juice. In a small bowl, mix together zest, orange juice, chicken broth, soy sauce and cornstarch; set aside. In another bowl, mix together garlic, ginger and oil; set aside. Set aside orange strips.
3. Drain beef and pat dry with paper towels. (Discard marinade.) Heat 1/2 tablespoon oil in a 12-inch non-stick frying pan over medium-high heat until smoking. Place half of beef in pan in an even layer and cook, without stirring, for 1 minute. Then flip beef slices and cook until browned around edges, about 30 seconds. (Do not overcook!) Transfer beef to a large plate. Wipe out skillet with paper towels. Heat another 1/2 tablespoon oil in skillet and repeat with remaining beef.
4. Heat 1 tablespoon oil in the same frying pan over medium-high heat. Add broccoli and cook about 1 minute. Add water, cover pan, lower heat to medium, and steam for about 2 minutes, or until tender but still crisp. Remove broccoli to a paper-towel lined plate and pour out any remaining water in pan.
5. Return beef and broccoli to pan over medium-high heat; clear the center of the pan and add the garlic, ginger and oil mixture along with the strips of orange peel. Sauté until fragrant, about 30 seconds. Add sauce to pan, stirring mixture constantly, until sauce thickens slightly, about 30 seconds. Serve immediately over rice and garnish with scallions.