Prepare beef by slicing thinly.
Combine all ingredients and let marinade overnight (or at least an hour)**.
Heat skillet*** on medium high heat. Add oil and spread around pan. Shake off the excess marinade on the beef (use chopsticks or tongs) and cook for 3~4 min. Note that it is very thin so it will cook quickly.
Enjoy! Serve with rice, ssamjang, kimchi, perilla leaves, lettuce, etc. anything you want!!