Marinate the Beef:

In a bowl, combine sliced beef, soy sauce, cornstarch, and sesame oil. Let it marinate for 15 minutes.

Prepare the Sauce:

Mix oyster sauce, beef broth, brown sugar, and rice vinegar in a small bowl. Set aside.

Cook the Broccoli:

Blanch or steam the broccoli until bright green and tender-crisp. Drain and set aside.

Sear the Beef:

Heat vegetable oil in a large skillet or wok over medium-high heat. Add beef in batches and sear until browned. Remove from pan.

Combine Ingredients:

In the same pan, sauté garlic and ginger for 30 seconds. Pour in the sauce and simmer for 2 minutes. Add beef and broccoli, toss to coat evenly, and cook for another 2–3 minutes until everything is heated through.