01 - Whisk together soy sauce, oyster sauce, hoisin sauce, cornstarch, water, sesame oil, sugar, and black pepper in a small bowl until smooth. Set aside until ready to use.
02 - Heat 1 tablespoon oil in a large wok or skillet over high heat. Add sliced beef and stir-fry for 2–3 minutes until browned but not fully cooked through. Transfer beef to a plate and reserve.
03 - Add remaining 1 tablespoon oil to the wok. Add minced garlic and grated ginger, stir-frying for 30 seconds until fragrant, being careful not to burn.
04 - Add asparagus pieces and sliced red bell pepper to the wok. Stir-fry for 2–3 minutes until vegetables begin to soften and develop a slight char.
05 - Add chopped bok choy to the wok and continue stir-frying for 2 minutes until wilted but still crisp-tender.
06 - Return the beef to the wok. Pour the prepared sauce over all ingredients. Stir-fry for 2–3 minutes until beef is cooked through and sauce has thickened to coat everything evenly.
07 - Taste the stir-fry and adjust seasoning with additional salt or pepper if needed. Serve immediately over steamed rice or noodles.