If you are going to eat this with something, like rice, start it at an appropriate time so it is ready at the same time.
Mix meat and marinade, set aside
Mix sauce ingredients, set aside
Clean greens,.
Cut into about 1 inch lengths, separate leaves from stems
Dice onion, I'm using a spring onion because I had some on hand
Into a skillet, wok or stir-fry pan, put about a tablespoon of oil, medium high heat. Put meat in, cook it until just done. Take it out, set aside.
Put pan back on heat, add more oil, put garlic and onion in. Stir fry 1 minute.
Add stems from greens.
Stir fry about 2 minutes until the stems are bright green, time depends on thickness of stems.
Add the leaves
Stir fry until wilted and cooked down
Add meat back in
Stir fry for 2 minutes, just to heat it through
Add sauce to center of pan
Stir fry 2 more minutes to heat and thicken sauce.
Add some rice into a bowl
Put beef & greens on top to serve
