
Tender slices of beef are quickly stir-fried with mushrooms, onion, and Chinese broccoli, then coated in a glossy oyster sauce. This Chinese takeout-style dish delivers savory flavor, crisp-tender vegetables, and an easy restaurant-quality finish at home.
Place the sliced flank steak in a bowl with the water, cornstarch, vegetable oil, oyster sauce, and baking soda, if using. Mix until the beef is evenly coated, then let it marinate for 30 minutes at room temperature or up to 4 hours in the refrigerator.
In a small bowl, whisk together the chicken stock, oyster sauce, sugar, cornstarch, dark soy sauce, and white pepper until smooth. Set the sauce aside so it is ready to pour into the wok.
Bring a wok or large pot of water to a boil and add 1 teaspoon oil. Blanch the Chinese broccoli for about 1 minute, or until just tender-crisp. Drain well without rinsing, then arrange it around the edge of a serving plate.
Heat the wok over high heat until lightly smoking. Add 1 tablespoon oil, spread the beef in a single layer, and sear briefly until just browned. Remove the beef from the wok before it cooks through completely.
Reduce the heat to medium. Add the remaining oil, then stir-fry the ginger for about 30 seconds. Add the garlic and cook for 10 to 15 seconds, just until fragrant.
Turn the heat back up to high and add the onion and oyster mushrooms. Stir-fry for 15 to 30 seconds until the onion starts to soften and lightly char. Pour in the Shaoxing wine, stir for another 30 seconds, then re-whisk the sauce and add it to the wok. Cook, stirring constantly, until the sauce comes to a simmer and thickens slightly.
Return the beef to the wok and toss until it is fully coated and just cooked through. Spoon the beef and sauce into the center of the plate with the Chinese broccoli and serve immediately.
For the most tender texture, slice the beef thinly against the grain. If Chinese broccoli is unavailable, use broccolini or bok choy. Do not overcrowd the wok when searing the beef, or it will steam instead of brown. Leftovers can be refrigerated in an airtight container for up to 2 days.