In a bowl, combine soy sauce, oyster sauce, brown sugar, cornstarch, and water. Mix well and set aside.
Heat 1 tablespoon of vegetable oil in a large pan or wok over medium-high heat. Add the sliced beef and stir-fry until browned. Remove the beef from the pan and set aside.
In the same pan, add another tablespoon of oil. Stir in minced garlic and grated ginger and cook for about 30 seconds until fragrant.
Add broccoli florets to the pan and stir-fry for a few minutes until slightly tender.
Return the cooked beef to the pan and pour the sauce mixture over the beef and broccoli. Stir well to coat everything in the sauce.
Cook for another 2-3 minutes until the sauce thickens and everything is heated through.
Serve hot over cooked rice.
Enjoy!