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.
Step 2: Rice
Fill about half or 2/3 of the rice you want to use in the plastic bag. Press it down a bit so the rice fills the corner of the bag.
Step 3: Fillings
Add in the fillings you want. I used some dried shredded fish and furikake (a Japanese condiment). You may want to bury the fillings in between the grains so that the ingredients are stuck well in the rice.
Step 4: Covering fillings
Cover the fillings with a bit more rice, however much you want.
Step 5: Forming the triangle
Press on all sides to make a triangle. Make sure it's pressed well so that it won't fall apart when you take the plastic bag off.
Step 6: Add nori
Take off the plastic bag and wrap a strip of nori/seaweed on the bottom to finish off.
Step 7: Final
And you are done! Serve on a plate or wrap it in plastic wrap for lunch packing or storage.