Pour all the liquid ingredients and the minced ginger into a bowl to create the marinade.
Slice the steaks into 2cm thick strips.
Place the steak strips and 120ml of the marinade into a bowl, cover the bowl and store the pair in the fridge anywhere from 15 minutes to overnight. Decant the rest of the marinade into an airtight container and refrigerate.
Preheat your grill (preferably charcoal, woodchip will also work well) to medium heat.
Slice the onions into 1cm thick slices, and thinly slice the napa cabbage.
Remove the steaks from the liquid marinade and discard this marinade. Season the steak slices with salt and pepper. Place your onions onto the grill. Grill the onions for 5 minutes.
Add your steak on top of this bed of onions. Continue grilling both of these ingredients for 15-18 more minutes (for medium-rare steaks). Remember to turn the steaks and onions occasionally.
Plate up the cabbage, move the onions and the steak straight onto the cabbage. Take the remaining marinade and drizzle over the top of the meat.
Serve to your adoring and grateful family.