With a Chinese wok, pre-heat it for 1-2 minutes over high heat. Add oil and beef, gently stir until beef slices change color. Add garlic slices, ginger slices, and green onion segments. Stir fry until fragrant. Add oyster sauce, light soy sauce, sugar, Zhenjiang sweet black rice vinegar (for fragrance), chicken broth, carrots slices, and broccoli florets. Stir to mix thoroughly. Then add potato slurry to thicken. Drizzle some sesame oil and stir to mix well. If you like spicy, you may add some chili pepper.