1. Peel the carrots, white radishes, potatoes, and sweet potatoes; boil them separately until soft, then mash them into a paste.
2. Add well-drained tofu, eggs, bean flour, and salt to the mixture; shape the mixture into four flattened meatballs, each 12 cm in diameter.
3. Deep-fry the shaped meatballs in oil until golden brown and set aside.
4. Crush the ginger and tie the scallions into a knot; sauté them in oil until fragrant. Add 100 ml of vegetable stock, dark soy sauce, sugar, pepper, MSG, yellow wine, baby bok choy, and the meatballs; simmer until the flavors are well absorbed.
5. Remove the ingredients from the pan. Arrange the bok choy hearts in a radial pattern on a plate and place the four meatballs on top. Thicken the remaining cooking liquid into a light sauce and pour it over the meatballs to serve.