Marinate beef for 15 minutes
In a hot wok, add oil, cook onion and mixed vegetables for couple minute, then add beef and cook for another few minutes. Transfer to a plate.
Slightly beat the eggs and season with salt. Add oil to the wok, then add eggs and wait until the eggs are half cooked, add rice and cook. Cook until the rice become slightly crisp. About 4 minutes.
Return the beef back to the rice. Add and kimchi to the rice. Stir for 2 minutes. Add oyster sauce and soy sauce, mix well. Season with salt.
Sprinkle with green onion.