Prepare all ingredients: slice the beef and broccoli, and measure sauces.
Marinate the beef slices in soy sauce and cornstarch for 10 minutes.
Heat vegetable oil in a large pan over medium-high heat.
Add beef to the pan and stir-fry until browned, about 3-4 minutes.
Remove beef from the pan and set aside.
Add garlic and ginger to the pan, stir-frying for 30 seconds.
Add broccoli and sauté for 2-3 minutes until bright green.
Return beef to the pan and mix well with broccoli.
Pour in beef broth and oyster sauce, stirring until combined.
Cook for an additional 2-3 minutes until the sauce thickens slightly.