Step 1: Velvet the Beef: Slice the beef against the grain into pieces about 3mm thick — thin enough to cook in under 90 seconds. In a bowl, combine the beef with the baking soda, cornstarch, soy sauce, wine, and water. Use your hands to massage the mixture into the meat until every drop of liquid is absorbed and the beef is evenly coated with a thin, glossy film. Let it marinate for 10 minutes. During this time, prep the broccoli, aromatics, and sauce.
Step 2: Blanch and Shock the Broccoli: Bring a pot of water to a boil. Add a teaspoon of salt and a few drops of oil. Drop in the broccoli florets and blanch for exactly 1 minute — no longer. Immediately drain and plunge the broccoli into a bowl of ice water. Let it sit for 1 minute, then drain thoroughly. The ice water halts the cooking instantly, locking in the vivid green color and crisp-tender texture. Blanching pre-cooks the broccoli so it only needs 30 seconds of stir-frying to heat through.
Step 3: Mix the Sauce: In a small bowl, whisk together the soy sauce, oyster sauce, cornstarch, sugar, and ½ cup of water until the cornstarch is fully dissolved. Set the bowl next to the stove. This sauce is the entire flavor backbone of the dish — the oyster sauce provides savory depth, the sugar balances the salt, and the cornstarch thickens everything into a clingy glaze.
Step 4: Sear the Beef Over High Heat: Set a wok or large skillet over high heat until it's smoking. Add 1 tablespoon of oil and swirl. Lay the marinated beef in a single layer — work in batches if necessary to avoid crowding. Stir-fry for 60–90 seconds, moving the pieces constantly, until they're browned on the outside but still slightly pink in the center. The beef will finish cooking when it returns to the wok. Transfer to a plate immediately.
Step 5: Combine and Glaze: Add the remaining 1 tablespoon of oil to the wok. Drop in the minced garlic and ginger and stir for 15 seconds until fragrant. Add the blanched broccoli and stir-fry for 30 seconds to heat through. Return the beef to the wok, give the sauce one last stir (the cornstarch settles), and pour it over everything. Toss vigorously for 30–60 seconds — the sauce will thicken almost immediately, turning glossy and clinging to every surface. Finish with the sesame oil, toss once, and serve immediately over steamed rice.