Wash the beef and bean sprouts thoroughly and prepare them.
Cut the beef into bite-sized pieces.
Add cooking oil to the pan and stir-fry the beef.
Season the beef with salt and pepper.
Once the beef is cooked, add the bean sprouts and stir-fry quickly over high heat.
Add soy sauce and sesame oil, and stir-fry once more.
Transfer to a plate and serve.