Fill a large heavy-based saucepan three-quarters full with water. Bring the water to a simmer, then add the carrot, daikon, coriander roots or stalks and garlic.
Stir in the sugar and light soy sauce and simmer over a very low heat for about 30 minutes, until the vegetables are soft and tender.
Meanwhile, cook the noodles according to the packet instructions, drain and set aside.
Blanch the bean sprouts, cabbage and tofu together in boiling water for 30 seconds. Drain and place in a serving bowl. Pour over the soup.
To serve, sprinkle over the pickled green cabbage, chopped coriander leaves, spring onion and crispy fried garlic. Finish with a dusting of white pepper. Serve with small bowls of light soy sauce, dried chilli flakes and sliced chillies in rice vinegar alongside, so everyone can season the dish according to taste.