Wash the bean sprouts thoroughly and drain them in a colander.

Chop the green onion finely. This step is optional.

Crack the eggs into a bowl, add a pinch of black pepper, and beat well.

Heat cooking oil in a pan over high heat, add the eggs, and stir-fry quickly.

Add the drained bean sprouts and oyster sauce to the pan, stir-fry quickly.

When the bean sprouts are slightly wilted, turn off the heat and mix in sesame oil.