
Bring 2 quarts of water to a boil. Rinse the bean sprouts and drain well. Thinly slice the scallions, separating the white and green parts. In a small bowl, stir together the soy sauce, dark soy sauce, sesame oil, salt, sugar, Shaoxing rice wine, and white pepper.
Cook the noodles until just tender. Fresh Hong Kong-style egg noodles usually need about 1 minute; dried noodles may need about 2 minutes or according to package directions. Drain, rinse under cold water to stop the cooking, and drain thoroughly so the noodles can crisp properly.
Heat a wok or large skillet over high heat. Add 1 tbsp vegetable oil and swirl to coat the surface. Spread the noodles into a thin, even layer and cook undisturbed for about 5 minutes, or until the bottom is crisp and lightly golden.
Carefully flip the noodles. Drizzle 1 more tbsp vegetable oil around the edges of the wok and cook the second side until crisp. If the noodles break apart, keep going; the goal is even browning and a dry, chewy-crisp texture. Transfer the noodles to a plate.
Return the wok to high heat and add the remaining 1 tbsp vegetable oil. Add the scallion whites and stir-fry for about 15 seconds until fragrant. Return the noodles to the wok, gently loosening any clumps. Pour in the sauce mixture and toss continuously for 1 to 2 minutes so the noodles are evenly coated and browned.
Add the bean sprouts and toss over high heat. Stir in the scallion greens and cook for 1 to 2 minutes more, just until the sprouts begin to soften but still have some crunch.
Transfer to serving plates and serve immediately while the noodles are still crisp.




