In a bowl, combine the sliced beef, 2 tablespoons of soy sauce, 1 tablespoon of cornstarch, and a pinch of salt and pepper. Mix well and let it marinate for about 10 minutes.
While the beef is marinating, prepare the broccoli by steaming or blanching it for about 2-3 minutes until it’s bright green and slightly tender. Set aside.
Heat the vegetable oil in a large skillet or wok over medium-high heat.
Add the marinated beef to the skillet, spreading it out evenly. Stir-fry for about 3-4 minutes until the beef is browned and cooked through. Remove the beef and set aside.
In the same skillet, add the minced garlic and ginger, and stir-fry for about 30 seconds until fragrant.
Add the steamed broccoli to the skillet and stir-fry for another minute.
In a small bowl, mix the remaining 1 tablespoon of soy sauce, oyster sauce, beef broth, and remaining 1 tablespoon of cornstarch until smooth. Pour this sauce over the broccoli and stir to combine.
Return the cooked beef to the skillet and stir until everything is coated in the sauce. Cook for an additional 2 minutes, allowing the sauce to thicken slightly.
Taste and adjust seasoning with salt and pepper as needed.
Serve hot over cooked rice.