Technique: How To Chop An Onion Like A Pro
1. Start with your onion on the cutting board. Do not peel it.
2. Slice off the sprout/stem end of the onion, but leave the root attached and intact. If you prefer, you can cut off a portion of the root (leaving the root core attached), but I find it easiest not to cut it at all.
3. Put the flat, cut side of the onion on the cutting board and slice straight down through the root, dividing the onion cleanly into two halves. At this point, peel the onion skin off each half.
4. Lay one half of your peeled onion on the cutting board. Then, make the first in a series of three cuts.
-For the first cut, with your knife parallel to the cutting board, slice toward the root end without cutting through. Repeat this cut at regular intervals, moving toward the top of the onion. This makes horizontal slices.
-For the second cut, place your knife with the tip end toward the root, and make vertical slices through the onion that are the same size as your horizontal slices.
-Finally, for the third cut, turn the onion and slice across it (knife parallel to the root) in the same thickness as the horizontal and vertical slices. This last cut produces the dice, and you can discard the remaining root end.
For photos/descriptions see: http://cilantropist.blogspot.com/2010/04/how-to-chop-onion-like-pro.html