Combine beef with marinade ingredients (light soy sauce, sesame oil, Shaoxing wine, MSG, cornstarch, baking soda, and salt) in a medium bowl

Massage the marinade into the meat for at least 30 seconds

Set aside for 15 minutes or refrigerate up to overnight

Combine dark soy sauce, light soy sauce, oyster sauce, and sugar in a small bowl and stir until homogenous

Combine cornstarch and water in a separate small bowl and stir with a fork until cornstarch is dissolved

Heat salted water in a wok over high heat until boiling

Add broccoli, cover, and cook until tender-crisp, about 1 minute

Drain broccoli and transfer to a plate to air-dry

Heat wok over high heat until lightly smoking

Add oil and swirl to coat

Add beef, spread into a single layer and let it cook until lightly seared, about 30 seconds

Stir-fry until beef is mostly cooked through with only a few pink spots remaining

Add garlic and ginger and stir-fry until fragrant, 30 to 45 seconds

Add Shaoxing wine by pouring it around the side of the wok

Stir sauce mixture and pour it in around the sides of the wok

Toss to combine

Add broccoli and toss to combine

Stir the cornstarch slurry and add a splash

Cook, tossing, until sauce thickens, about 30 seconds

Adjust sauce consistency with more cornstarch slurry if too thin, or water if too thick

Transfer to a serving platter and serve immediately with steamed white rice