Heat 1 tablespoon of oil in a large flat-bottom wok or skillet over medium-high heat. Add the ground beef and cook, breaking it into large pieces, until browned and crispy, about 4-6 minutes. Season with 1/4 teaspoon salt, then transfer to a bowl.
In a small bowl, whisk together the rice vinegar, Shaoxing wine, sesame oil, fish sauce, sugar, and white pepper. Keep it near the stove as the sauce will be used later.
Heat the remaining 2 tablespoons of oil in the same pan. Add the green beans and cook, stirring occasionally, until they achieve a slight char and are tender, about 4-6 minutes.
Stir in the scallion whites, garlic, and ginger. Cook until fragrant, approximately 1 minute.
Return the ground beef to the pan along with the sauce and the remaining 1/4 teaspoon salt. Stir well until the ingredients are evenly coated, about 1 minute.
Serve hot, garnished with scallion greens for a fresh pop of flavor.