1. Grind coriander root, garlic and peppercorn in a mortar and pound until mixed thoroughly (or using food processor). Then mixed with minced pork and fish sauce (1 tbsp). Let marinate for 15-20 minutes.
2. Heat soup in a pot over medium heat. Add marinated pork and wait until nearly cooked. Then add prpepared cabbage in the pot.
3. Season with soy sauce, ground pepper, fish sauce and sugar. Stir until the pork and the cabbage are thoroughly cooked. Remove from heat.
4. Transfer to a serving bowl. Sprinkle with coriander leaves and chopped scallion. Serve immediately with hot steamed rice.