Prepare the vegetables by chopping them julienne. Set aside.
Marinate the beef with soy sauce, sesame oil, garlic, and black pepper. Set aside.
Boil the rice cakes until soft and easy to pinch but do not break. Drain and rinse it in cold water then marinate with soy sauce and sesame oil.
In high heat, saute the marinated beef. When 50% done, add onion, carrots, and garlic, then continue sauteing.
Add oyster mushroom, enoki mushroom, and pepper, then continue sauteing.
Add the rice cakes and season with soy sauce, oyster sauce, sugar, and black pepper. Mix thoroughly until everything is well coated.
Serve immediately and enjoy!