Slice the onion. Heat a wok with water until boiling, and cook the noodles, then transfer it on clear water immediately. Drain and set aside.

Beat 1 egg in a bowl. Heat a wok with oil, and stir-fry egg well. Transfer it on a plate. Add the onion in the wok and continue to stir-fry it until soft. Add the fat beef and continue to stir-fry a few times. Sprinkle the cumin and stir well.

Add noodles, 1 tablespoon of light soy sauce, 1/2 tablespoon of dark soy sauce, sugar and salt in the wok. Stir-fry them evenly. Then add the egg and stir-fry them well. Transfer on a plate and serve.