Learn how to properly chop an onion.
Step 1. Chop an onion in half making sure your knife cuts through the tip and the root.
Step 2. Remove the tip of the onion and peel outer skin.
Step 3. Horizontally slice the onion keeping one edge of onion for finger placement.
Step 4. Next, slice onion vertically.
Step 5. Turn onion, and again slice vertically.
Watch the "pinch tips" video here.