For the meatballs:
Put the ground beef, rice wine, garlic, spring onions, egg, ginger, soy sauce, sesame oil, cornstarch, salt, and white pepper into a large bowl to combine, stirring in the same direction.
Using wet hands, scoop a large mound of the ground meat mixture, and mold it into a ball. The size should be a little larger than a golf ball. Transfer the meatball to a plate and repeat with the remaining mixture.
For the assembly:
Pour the groundnut oil into a large deep pan, and heat over a high heat. Using a metal ladle, carefully lower each meatball into the oil, and spoon some of the oil over the meatballs. Cook for 4 to 5 minutes, or until browned.
Pour all but 2 tablespoons of oil into a heat-proof bowl. Add the vegetable stock to the pan. Arrange the quarters of Chinese cabbage around the meatballs, curving them lengthwise around the sides of the pan, then add the mushrooms, and soy sauce. Bring everything to a boil. Cover the pan, reduce its heat, and cook gently for 15 minutes. Add the blended cornstarch slurry, if using, and stir until the sauce thickens.
Remove the pan from the heat, and season with salt, and white pepper, to taste, and sprinkle over the spring onion slices. Transfer the dish to a warm serving platter, and serve immediately.
Heat a pan, add the rice and water, cover, and cook over high heat for 15 minutes.
Reduce the heat to very low, and cook for an additional 3 minutes, making sure all the water has evaporated. Remove from the heat and, using a spatula, fluff the rice. It is now ready to serve.
Steamed or glutinous rice is a perfect accompaniment to this dish.