Combine soy sauce, honey and vinegar in a mixing bottle or jar with a tight lid
Add garlic powder and ginger
Add salad oil and onion and mix well
Set aside marinade
Prepare meat by stripping off excess fat
Slash lightly on the diagonal (on each side) in diamond cuts
Place meat in a small pan just big enough to hold it (You can use a gallon sized baggie if big enough to hold the steaks)
Pour marinade over steaks
Cover
Allow to stand at room temperature 2 hours or place in the refrigerator overnight
When ready to cook, remove steak from marinade and place on grill using medium heat
This meat cooks fast; about 6 minutes per side for medium rare. If you want medium, add 2-3 minutes per side
To serve, slice thinly on the diagonal