Onigiri, also known as rice ball, is made with white rice that is usually formed into a triangular or circular/oval shape wrapped with a strip of nori (edible seaweed). Some traditional fillings for onigiri include pickled vegetables or fruit (plum), fish (salmon, tuna), seafood, and any other salty or sour preservatives. But you can always add whatever ingredients you like for the fillings. To make a triangular onigiri, it is done by shaping it into a triangle by hand. It may be a bit messy and may take a while to form the perfect triangle. So this instructable shows a clean, quick, and easy way to make a triangular onigiri using a plastic bag.
Step 1: Cut out plastic bag’s edge
First, take a clean plastic bag and cut off an edge of the bag so it becomes a triangle. The measurements for mine are about 7 inches X 10 inches X 7 inches. It's also great to use an empty chip bag but it's easier to see what you are doing with a clear plastic bag or Ziploc bag.