Marinate the beef

• Slice the beef thinly against the grain and place in a bowl.
• Toss with part of the soy sauce and the cornstarch until coated.
• Let it sit while you prepare the rest.

Mix the sauce

• Stir together the remaining soy sauce, oyster sauce, brown sugar, sesame oil and water.
• Whisk until the sugar dissolves.

Blanch the broccoli

• Bring salted water to a boil in a saucepan.
• Cook the broccoli florets until bright green and crisp-tender.
• Drain and set aside.

Sear the beef

• Heat the vegetable oil in a wok over high heat.
• Add the beef in a single layer and sear without stirring until browned.
• Remove the beef and set aside.

Stir-fry the aromatics

• Add the garlic and ginger to the wok.
• Stir-fry until fragrant, without browning.

Combine and finish

• Return the beef to the wok with the broccoli.
• Pour in the sauce and toss over high heat until it thickens and coats everything.
• Sprinkle with sesame seeds and serve hot.