Slice the beef thinly. Freeze the steak for 20–30 minutes to firm it up. Using a sharp knife, slice it thinly against the grain into bite-size strips. Thinner slices cook quickly and stay tender.

Marinate and tenderize. In a bowl, toss the beef with 1 tablespoon soy sauce and 1 tablespoon cornstarch. Add 1 teaspoon oil. Let it rest for 10–15 minutes while you prep the other ingredients. This gives a light velveted coating.

Prep the broccoli. Cut the florets into even pieces. If using stems, peel the tough exterior and slice thinly so they cook at the same pace.

Make the sauce. In a small bowl, whisk together remaining soy sauce, oyster sauce, brown sugar or honey, rice vinegar or Shaoxing wine, beef stock or water, and 1 tablespoon cornstarch. Stir until smooth. Adjust sweetness and salt to taste.

Blanch or steam the broccoli. Bring a pot of salted water to a boil and cook broccoli for 1 minute, then drain and rinse with cold water to stop cooking. Alternatively, steam for 2–3 minutes until bright green and crisp-tender. This step keeps it vibrant and not soggy.

Heat the pan. Set a large skillet or wok over medium-high heat. Add 1–2 tablespoons neutral oil and swirl to coat. You want it hot but not smoking.

Sear the beef in batches. Add a single layer of beef and let it sear undisturbed for 30–45 seconds, then stir-fry until mostly browned but not fully cooked through, about 1–2 minutes. Transfer to a plate and repeat with remaining beef if needed. Don’t crowd the pan.

Sauté aromatics. Reduce heat slightly. Add a touch more oil if the pan is dry. Stir-fry garlic and ginger for 20–30 seconds until fragrant. Avoid burning.

Combine and sauce. Return the beef to the pan along with the broccoli. Give the sauce a quick stir, then pour it in. Cook, tossing, for 1–2 minutes until the sauce thickens and coats everything.

Finish and serve. Turn off the heat and stir in sesame oil. Add red pepper flakes if you like a kick. Garnish with green onions and sesame seeds. Serve hot over steamed rice.