1) First, your whole onion should have a root side and a stem side. Chop off the stem side so you have a flat surface on that side, and keep the hairy root side intact.
2) Now, lay your onion on your work surface with the newly flat surface acting as a stabilizer. Slice the onion in half through the hairy root, and peel off the layers of onion skin.
3) Before you start chopping, it's important to keep in mind that you should not slice or cut through the root until the very end. Leave about a quarter of an inch from the root clear when chopping.
4) Lay your halved onion flat side down on your chopping board so that it is stable. Place your non-chopping hand very flat across the top of the onion. Turn your knife parallel to the table, and do two to three cuts into the onion (remember: not all the way to the root!).
5) Remove your hand from on top of the onion, and you'll see that there are some natural lines that are part of the onion's skin. With your non-chopping hand in a bear-claw shape, use the natural lines as rough guidelines for where to cut downwards, keeping clear of slicing through the root.
6) Now, turn the onion 90 degrees and cut the onion in the opposite direction (cross-wise). Can you believe it? You're chopping an onion with pizzazz!
7) If you need to, cut around the root and slice the remainder of the onion.
VOILÀ! You have a diced onion! You're ready to take it to the next level: mincing garlic.