Start by slicing the beef into thin strips, against the grain, to ensure tenderness.
In a mixing bowl, toss the beef slices with 1 tablespoon of cornstarch until evenly coated. This will help to tenderize the meat and thicken the sauce.
Wash and cut the broccoli into bite-sized florets.
In a small bowl, whisk together the soy sauce, oyster sauce, brown sugar, ground ginger, and beef broth. Set this sauce mixture aside.
Heat 1 tablespoon of vegetable oil in a large skillet or wok over medium-high heat.
Add the beef slices to the skillet and cook for about 2-3 minutes, or until the beef is browned and cooked through. Remove the beef from the skillet and set it aside.
In the same skillet, add the remaining tablespoon of vegetable oil.
Add the broccoli florets and minced garlic, stirring frequently. Cook for about 3-4 minutes, or until the broccoli is tender but still crisp.
Return the cooked beef to the skillet with the broccoli.
Pour the sauce mixture over the beef and broccoli.
Stir everything together until the beef and broccoli are evenly coated with the sauce.
In a small bowl, mix 2 tablespoons of cornstarch with 2 tablespoons of water to create a slurry.
Pour the slurry into the skillet and stir continuously until the sauce thickens to your desired consistency. This should take about 2 minutes.
Serve: Remove the skillet from the heat.
Serve the beef and broccoli hot over cooked white rice.