In a mixing bowl, combine thinly sliced flank steak with baking soda, Shaoxing wine, light soy sauce, oyster sauce, white pepper, water, and cornstarch. Mix thoroughly and let it marinate for at least 15 minutes.

In a separate bowl, whisk together oyster sauce, light soy sauce, dark soy sauce, Shaoxing wine, sugar, chicken broth, and cornstarch until fully blended.

Bring a large pot of salted water to a rolling boil, then carefully add the broccoli florets. Blanch for 1-2 minutes until bright green, then drain and rinse under cold water.

In a hot wok or large skillet, heat a tablespoon of cooking oil until shimmers. Add the marinated beef in a single layer and cook for approximately 30 seconds on each side until browned.

Add more oil, minced garlic, and ginger to the wok. Sauté for about 30 seconds, then add the blanched broccoli and stir-fry for an additional minute. Return the cooked beef and stir-fry sauce to the pan.

Remove the pan from heat and drizzle with toasted sesame oil. Toss everything to combine the flavors.

Transfer to serving plates and serve immediately over white rice, quinoa, or cauliflower rice.