1. In a large saucepan, combine the pork stock, 2 tablespoons miso, garlic, star anise, ginger and 2 cups water. Bring to a boil over medium-high heat and cook, stirring occasionally, until the broth is rich and fragrant, about 30 minutes. Strain the broth through a fine strainer and stir in the remaining 2 tablespoons miso. Season with salt and pepper and stir in the sesame oil.
2. Split the cooked noodles between 4 bowls. Pour the hot broth over the noodles. Serve with toppings on the side and have everyone personalize their own bowl of noodles.