Segment the scallions into 3-inch pieces and separate the whites and light greens from the dark greens. (Dry the scallion segments well, so that they don’t splatter in the oil.)
In a mixing bowl, whisk together the light soy sauce, dark soy sauce, oyster sauce, sugar and Shaoxing wine.
Combine the vegetable oil and lard in a wok and heat them up on medium until the lard is fully liquified.
Add the scallion whites and light greens to the oil mixture and cook for 8 minutes, or until they are fully soft and the edges are lightly toasted. Remove them from the oil with a spider and set them aside. Turn the heat to low, then add the dark green parts of the scallions and cook them until they are fully soft and the edges are lightly toasted, another 8 minutes or so. Remove the greens from the wok and set them with the whites.
Add the sauce mixture to the oil. Once the sauce begins foaming, cook for another two minutes while stirring vigorously to dissolve the sugar and meld the flavors. You will not achieve a fully emulsified mixture, and you are not meant to. Set the sauce aside, but cover to keep warm (or refrigerate to store; see below).
To make the finished dish, cook the noodles according to the package instructions, rinse off the excess starch and divide them between four individual bowls. Top each bowl with a generous pile of crispy scallions and 3–4 spoonfuls of sauce, or more if the heart desires.