Prepare all ingredients: slice beef, chop broccoli, mince garlic, and grate ginger.

In a bowl, whisk together soy sauce, sesame oil, cornstarch, garlic, and ginger to form the sauce.

Heat a large skillet or wok over high heat; add vegetable oil until shimmering.

Sear the beef in a single layer for about 2 minutes without stirring. Flip and cook for another minute until browned; remove from pan.

In the same pan, stir-fry broccoli for about 3 minutes until bright green but still crunchy.

Return beef to the pan and add the sauce mixture; stir for another minute until everything is well coated.

Serve hot over rice or noodles.