Marinate the beef

• Add the thinly sliced flank steak to a bowl with the cornstarch, garlic paste, dark soy sauce, oyster sauce, garlic powder, white pepper, ginger paste, baking soda, rice wine vinegar, Shaoxing wine and salt.
• Mix well until the beef is evenly coated.
• Let marinate.

Prepare the sauce

• In a bowl, whisk together the chicken broth, oyster sauce, dark soy sauce, soy sauce, brown sugar, minced garlic, MSG, rice wine vinegar and Shaoxing wine.
• Set aside.

Cook the noodles

• Cook the lo mein noodles according to the package directions.
• Drain well and toss with a drizzle of sesame oil to prevent sticking.
• Set aside.

Sear the beef

• Heat a large wok over high heat and add a little oil.
• Cook the beef in batches if needed to avoid overcrowding.
• Sear until browned and almost cooked through, then remove and set aside.

Cook the vegetables and noodles

• To the same wok add the broccoli and shredded carrots and cook until tender.
• Add the lo mein noodles and toss until well combined.
• Add in the beef and mix.

Add the cornstarch slurry

• In a small bowl, whisk together the cornstarch and cold water until completely smooth.
• Give the prepared sauce a good stir, then whisk in the cornstarch slurry.

Finish the lo mein

• Pour in the sauce and toss everything together over medium-high to high heat, tossing continuously, making sure the sauce coats the noodles, beef and vegetables evenly.
• If the sauce becomes too thick, add a small splash of broth or noodle water.

Garnish and serve

• Garnish with sesame seeds and serve hot.