Thinly slice the beef against the grain at a 45° angle to create ¼” thick strips that are 3 inches wide. Add the beef to a bowl and marinate with baking soda, oyster sauce, Shaoxing wine, soy sauce, and cornstarch for 15 minutes.
Cut the bell peppers and onion into 2” pieces. Finely mince garlic and ginger and set aside.
Mix sauce by combining beef stock, oyster sauce, soy sauce, Shaoxing wine, dark soy sauce, sugar, white pepper, black pepper, sesame oil and cornstarch.
Heat a wok or skillet on high with 2 tbsp of neutral oil. Sear beef for 2-3 minutes or until 80% cooked through and remove.
Heat 1 tbsp of neutral oil over medium high heat, sauté the garlic and ginger for 30 seconds followed by the onions and bell peppers. Cook for 1-2 minutes.
Add back the steak followed by the sauce and cook until the sauce has reduced and is thickened and glossy, about 2 minutes. Serve with white rice and enjoy!