1.Cut the leeks and scallions into short sections.
2.Heat a wok over a medium heat and add the water and sugar. Cook until the sugar starts to caramelise and then add the light soy sauce. Continue cooking until all the sugar has dissolved and then set aside to cool.
3.Heat the oil in a wok over a low to medium heat and then add the leeks and ginger. When the leeks have turned a deep golden brown, remove from the wok and add the scallions and deep-fry until dry. Increase the heat under the wok until the oil reaches 200℃ and then turn off the heat and set the oil aside.
4.Cook the noodles in boiling water according to packet instructions.
5.To serve, place 2 tbsp of soy sauce and 2 tbsp of scallion oil in each noodle bowl, top with a portion of noodles, then finish with the deep-fried scallions. Stir well before eating.