Hold your knife at a 45-degree angle will make the slice wilder and more flat. Slice the beef against the grain into thin pieces at about ⅛” thin.
Tenderize and marinate
In a bowl, add the beef and season with ingredients from coconut aminos to sesame oil, if using. Gently stir and mix well. Cover the bowl and marinate the meat for 15 to 30 minutes in the fridge or up to 1 day in advance. Your beef is ready for stir-frying!
Notes
You do not need this ingredient if you use soy sauce.
For beef strips, after thinly slicing the beef into pieces, stack a few pieces to cut into thin strips. I recommend freezing the steak for half to 1 hour before slicing; it'll be easier to cut.
For beef cubes, dice them into similar size cubes so they cook evenly at the same time and temperature.
Make-ahead: Slice the beef and marinate it in an airtight container or freezer-friendly bag in the fridge or freezer. (Lay the bag flat if you’re going to freeze it so it’s easier to defrost.)
Storage: You can marinate the meat up to 3 days in advance, but overnight is best.
Freeze: Leftoversof stir-fried meat or uncooked, marinated beef strips can be stored in the freezer for up to 3 months. Defrost the night before in the fridge.