Wash the bean sprouts thoroughly and remove excess water using a vegetable spinner.

Slice the chili pepper and green onion; cut the fish cake into thin strips similar in length to the bean sprouts.

Heat 1 tbsp vegetable oil in a pan, add the fish cake, soy sauce, and 1/2 tsp sugar. Stir-fry until golden brown, then set aside.

In the same pan, add 2 tbsp vegetable oil and heat. Reduce to low heat and add 1 tbsp red pepper flakes to create chili oil.

Add the bean sprouts to the pan and stir to coat them evenly with the chili oil.

Add oyster sauce, 1 tsp sugar, and minced garlic. Increase the heat to high and stir-fry until the bean sprouts are slightly wilted.

Add the sliced green onion and chili pepper, season with salt, 1/2 tbsp red pepper flakes, and a pinch of black pepper.

Return the cooked fish cake to the pan and mix well with the bean sprouts.