Season the beef with the marinade ingredients (dark soy, cooking wine, soy, baking soda, white pepper) and the cornstarch. Mix until well combined and marinate 15 minutes.
Make the sauce: combine the oyster sauce, dark soy, soy, chicken bouillon, sugar, white pepper and sesame oil. Mix well.
Heat a wok over medium heat and add ⅓ cup oil. Add the beef, spread it evenly, and cook about 3 minutes per side (about 6 minutes total). Remove.
In the same oil, sauté the minced garlic and grated ginger for about 1 minute.
Add the white onion and sauté about 2 minutes, until slightly translucent.
Return the beef to the pan, add the sauce, and cook about 2 more minutes.
Toss in the green onion and serve over white rice.
Ready in under 30 minutes. Method transcribed from the video (rough). From lov.kari on Instagram.