Preheat a large pot with oil. Add in garlic, ginger, and onion. Saute until the onion is soft, about 2 minutes. Add in the pork and saute until they turn color. Add in mirin, dried chili, and chili powder. Add in the carrot and the stock. Bring to a boil and then let it gently simmer until the carrots are soft but not mushy. Have a taste on the soup and season with soy sauce and a pinch of salt if needed
When ready to serve, bring the soup back to a boil, portion the noodles and vegetables out into individual serving bowls. Add in the seafood into the soup (you don't want to do this early because seafood is easily overcooked, do this when you ready to serve the noodle). They should cook quickly. Discard any mussels that do not open. Portion the seafood into the serving bowl. Generously ladle the hot broth over. Garnish with chopped spring onion and serve immediately