Bring plenty of water to a full boil. Add the noodles. Leave to boil over medium heat until they are just cooked.
Heat the stock
While the noodles are cooking, use another pot to heat up the stock over another burner until it becomes piping hot.
Prepare the seasonings
As the above two steps are in progress, add all the seasonings to two serving bowls — light soy sauce, dark soy sauce, sesame oil (or lard, rendered chicken fat), and white pepper.
Assemble the dish
Ladle the hot stock over the seasonings. Stir well and taste the soup to decide if additional salt is needed. Add the cooked noodles. Sprinkle chopped scallions over and serve immediately.
Notes
1. For one portion, fresh noodles weigh around 5 oz (140g) and dried noodles weigh about 3 oz (85g).2. Sesame oil is a more accessible alternative to lard (aka rendered pork fat), the traditional option for this dish. Rendered chicken fat is a good substitute too.