When I began culinary school, one of the few things I thought I already knew was how to dice an onion. Turned out I was right, and I was wrong. My way wasn’t incorrect, but there was a faster and safer way to do it. Here’s how I’ve been dicing onions ever since.
1. Trim the ends but leave much of the root intact. Cut the onion in half from end to end and peel each half. Lay one half on its cut side. Make parallel vertical cuts from root to stem end, but not completely through the root end. Space the cuts as wide as you want your dice.
2. Make one or two horizontal cuts, again being careful not to cut through the root end. Whether you make one or two horizontal cuts depends on the size of the onion.
3. Make a series of cuts perpendicular to the cuts from step 1, again spacing them as wide as you want the dice to be. Keep the fingers of your guiding hand curled so you don’t cut your fingertips.
4. When you get close to the root end and the cutting becomes awkward, flip the onion root side up as shown and slice across it one or two times.
5. Flip the onion back to how it was in step 3. The top is now flat and easier to dice. Finish dicing down to the root. Discard the root and repeat with the other onion half.