Ok, I can’t guarantee that you’ll never shed a tear cutting up an onion. What I can deliver you from is tears of frustration. Trust me, that’s a big deal. After all, what’s the least fun part about cooking? The prep. If you can find tricks to make the process easier and faster, you will enjoy the prep more, and you will be more likely to cook more often. Plus, it appears (from observational evidence, not scientific evidence – that I know of, anyway) that when you cut this way, leaving the root end intact, that you are far less likely to cry from stinging onion-y eyes (unless the onion is too old to be cooking with. I can’t help you then, sorry).
So, without further adieu, I give you the spoke method of chopping onions!
Use a good, sharp chef’s knife. The job will be easier with a knife with a tall blade rather than a short one (like found on a boning knife). Use a thin knife if you have the option – I cut onions with my Henckels Twin Four Star II Santoku knife, which has a thinner blade than my traditional chef’s knife. Don’t worry about cutting yourself – this method is much safer than many others I’ve seen.
Begin by cutting off the sprout end of the onion (i.e. the one without the stringy roots). Slice the onion in half lengthwise, so that you are cutting through both the sprout and the root ends (north-south), instead of avoiding them (east-west). Peel back the skin of the onion. It will still be attached at the root end, so just yank it off.
Begin by making a straight cut perpendicular to the board. Do not cut all the way to the root. You will want to leave about 1/4-1/2 an inch of onion intact where it terminates at the root.
Rotate your knife blade to the side a bit and make a similar cut into the onion like a spoke on a bicycle wheel. Repeat, rotating the blade more with each cut, until you can’t feasibly make any more cuts. Repeat the process on the other side of the onion.
Your onion should now look something like this:
Your root end should still be holding the onion together. Some loose bits of onion may try to escape from the bottom or the sides where your cuts may not have made it all the way to the center of the onion before hitting the board, but that’s ok.
Rotate the onion ninety degrees and begin slicing vertically. Uniformly-sized onion dice is the result!
The layers will separate on their own, resulting in no need to cut the onion further. This is the result I got just by sweeping the onion dice aside out of its nice pile – I didn’t make another single slice!