In a small bowl, mix oyster sauce, rice wine, sesame oil, crushed garlic, ground black pepper and set aside.
Cut steak into 1" square cubes - any smaller the beef will be overcooked. Make sure they are all about equal size to cook evenly. Salt slightly and set aside.
Cut scallions on the bias about 1 inch long and set aside.
Slightly oil a skillet with vegetable oil and heat over medium high heat.
Sear the beef and scallions together for about a minute. Do not move beef to let it caramelize on one side.
Turn each beef cube and sear on the other side for a minute.
Add sauce to skillet (avoid inhaling the black pepper fumes), coat beef and scallions and toss for about a minute.
Plate and garnish with sesame seeds.