Boil the chicken breast and shred it along the grain.
Soak the jangpi (mung bean sheet) in hot water for 5 minutes, then drain thoroughly using a strainer.
Julienne the cucumber, carrot, bell pepper, and onion into thin strips.
Blanch the bean sprouts in boiling water, then rinse in cold water.
Beat the eggs and make a thin omelette in a pan without oil, then cut into strips.
Arrange all the ingredients neatly on a plate.
Mix soy sauce, vinegar, sugar, and mustard to make the sauce and serve on the side.