Start by patting dry the scallions (very important or else oil will fly out crazily when frying). Cut scallions into 2-inch pieces.
Add the ginger, shallots, and ONLY the white and light green parts of the scallion stalks to a pot/wok. Pour just enough oil to cover them. Turn the heat to medium-low and let it sizzle for around 10 minutes. Remove from the pot and set aside.
Add in the green parts of the scallions and fry for 5 to 10 minutes, keeping a close eye on them so they don’t burn (throw out any burned pieces). Remove the scallions from the pot/wok and set aside with the fried ginger and shallots. Don’t throw this out! It makes a good topping for your noodles.
Sieve the scallion oil and let cool. It can be kept in the fridge for up to 3 weeks.