For the Scallion Oil
Heat the oil and fry the onion. Take out when they turn golden brown.
Add the green part of the scallion into the oil, fry over low heat for about 5 mins then take out.
Add the white part of the scallion, fry over low heat till golden brown, take out and set aside.
For the Noodles
Mix 2-3 tbsp scallion oil with dark soy sauce, light soy sauce and sugar in the serving bowl.
Boil noodles with water till cooked, take out with a strainer spoon.
To serve, mix noodles with oil sauce, then add some fried white scallion on the top.