In a bowl, combine the sliced beef with 1 teaspoon of cornstarch and 1 tablespoon of soy sauce.

Mix well to coat the beef and set it aside to marinate while you prepare the other ingredients.

In a separate bowl, mix together the beef broth, 2 tablespoons of soy sauce, sesame oil, oyster sauce, and the remaining 2 teaspoons of cornstarch.

Whisk until well combined and set the sauce mixture aside.

Heat a wok over medium-high heat and add peanut oil.

Once the oil is hot, add the minced garlic and ginger. Sauté for about 30 seconds until fragrant.

Add the marinated beef to the wok and stir-fry for about 5 minutes, or until the beef is mostly cooked through.

Add the broccoli florets to the wok and season with black pepper.

Stir well to combine.

Pour the prepared sauce into the wok and stir everything together.

Continue to cook for another 2 minutes, or until the sauce has thickened and the broccoli is tender-crisp.

Remove from heat and serve hot over steamed rice.