Bring a large pot of water to a boil and cook noodles until al dente. Drain and set aside with a drizzle of oil.

Place finely chopped scallions in a large heatproof bowl.

Heat 4 tbsp neutral oil in a small saucepan over medium-high heat until shimmering.

Pour hot oil carefully over the scallions — you should hear a sizzle.

Add light soy sauce, dark soy sauce, sugar, salt, and optional oyster sauce. Stir to combine.

Add cooked noodles to the scallion oil and toss evenly.

Garnish with chili crisp or sesame seeds and serve immediately.