Put the beef in a deep bowl and make the marinade.
NOTE FOR THE MARINADE, season it according to your liking, but this is what I used. Adjust the mixture in a small bowl and if it good enough for you, pour it into the beef and mix. Marinate meat overnight.
WHEN MEAT IS ready, heat 1 tablespoon, or more, cooking oil and lightly brown the beef in all sides. This process doesn't take long to cook since the beef is very thinly sliced. When ready, set aside.