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

Slice the green onion thinly and set aside.

Cut the ham into thin strips, similar to bacon. Optionally, blanch the ham briefly in hot water to remove excess grease.

Slice the chili pepper diagonally into small pieces.

Heat vegetable oil in a pan over medium-low heat and sauté the green onion until fragrant.

Add the ham and chili pepper to the pan and stir-fry until they are slightly cooked.

Increase the heat to high and add the bean sprouts and oyster sauce. Stir-fry quickly until the bean sprouts are slightly tender.

Turn off the heat and add sesame oil. Stir quickly using residual heat and transfer to a plate immediately.