In a bowl, add the sliced beef, ¼ teaspoon baking soda, and 3 tablespoons water (if you don’t want your beef tenderized too much, omit the baking soda). Massage the beef with your hands until all the liquid is absorbed. Mix in 1 ½ teaspoons cornstarch, 2 teaspoons oil, and 1 teaspoon oyster sauce, and set aside to marinate for at least 30 minutes.
Make the sauce mixture by mixing together the chicken stock, sugar, soy sauce, dark soy sauce, oyster sauce, sesame oil, and white pepper. Set aside.
Bring 6 cups of water to a boil and blanch your broccoli for 30 to 60 seconds (depending on whether you like your broccoli crunchy or a little soft). Drain and set aside.
Heat your wok over high heat until smoking. Add 2 tablespoons oil and sear the beef on both sides until browned (this should only take 2-3 minutes). Turn off the heat, remove the beef from the wok, and set aside.
Set the wok over medium heat and add another tablespoon of oil to the along with the garlic and ginger (if using). Stir the garlic and ginger for 5 seconds and then pour the Shaoxing wine around the perimeter of the wok.
Next, add in the sauce mixture you made earlier. Stir the sauce around the sides of the wok to deglaze it (all those nice bits from stir-frying the beef should be absorbed into the sauce). Bring the sauce to a simmer. Stir the cornstarch and water into a slurry to ensure it’s well combined, and drizzle the mixture into sauce while stirring constantly. Allow it to simmer and thicken for 20 seconds.
Toss in the blanched broccoli and seared beef (along with any juices). Mix everything together over medium heat until the sauce coats the beef and broccoli. If the sauce seems thin, turn up the heat and reduce it further, or add a bit more cornstarch slurry. If the sauce is too thick, add a splash of chicken stock or water. Serve with plenty ofsteamed rice!