Preparation Steps

• Partially freeze the flank steak for 10 minutes to firm it up, then slice thinly against the grain.
• In a bowl, whisk 1.5 tbsp soy sauce, Shaoxing wine, brown sugar, 2.0 tsp cornstarch, baking soda, half the ginger, and 1.0 minced garlic clove. Add beef and toss to coat; marinate 15 minutes while you prep vegetables.
• Make the sauce: In a cup, stir together beef broth, remaining 1.5 tbsp soy sauce, oyster sauce, rice vinegar, remaining ginger and garlic, and black pepper. In a separate small cup, mix 1.0 tsp cornstarch with 1.0 tbsp water to make a slurry; set both aside.
• Heat a large skillet or wok over high heat until very hot. Add 1.0 tbsp oil and half the beef in a single layer. Sear 60 to 90 seconds until browned but still pink inside. Transfer to a plate and repeat with remaining 1.0 tbsp oil and beef.
• Add onion and red bell pepper to the empty pan. Stir-fry over high heat for 2 minutes until crisp-tender.
• Return beef and any juices to the pan. Pour in the sauce and bring to a rapid simmer. Stir in the cornstarch slurry and cook, tossing, until the sauce turns glossy and lightly thickens, about 1 to 2 minutes.
• Turn off heat and finish with sesame oil and red pepper flakes (if using). Taste and adjust seasoning with a pinch more soy sauce or black pepper as desired.
• Serve immediately over cooked white rice and garnish with sliced scallions.