Make dipping sauce by combining all the ingredients in a small bowl and whisking together. Cover and set aside in fridge.
Use a meat mallet to hit the steak a few times, tenderizing the meat.
Cut the red onion into large chunks and place them in a bowl with pickle juice and black pepper.
Add the steak to the pickle juice mix, cover and refrigerate for 3-5 hours.
Grill or pan fry the steak for 2-3 minutes on each side. Remove from the grill and cover with foil to rest, allowing the juices to absorb into the meat.
Grill the marinated onion chunks in a grill wok or simply place on top of a piece of foil on the grill to cook. Sear for about 8 minutes, until they begin to have black grill marks. Remove from the grill.
Cut the pickles in fourths.
Slice the meat very thinly across the grain, making long ribbons.
Skewer a pickle, grilled onion and beef ribbon onto a toothpick. Repeat with the remaining ingredients. Enjoy with dipping sauce.