How to Dice an Onion?

The reliable chef's method: halve the onion through the root, leave the root end intact to hold it together, make vertical cuts toward the root, then slice across those cuts to produce even dice.

What you need: a sharp chef's knife and a stable cutting board. A dull knife crushes the cells, which releases more of the compound that makes you cry.

Step-by-step:

1. Trim the top. Slice off the stem end (the papery top), but leave the hairy root end on — it's the handle that keeps the layers together while you cut.
2. Halve it through the root. Cut from the trimmed top straight down through the root, giving you two halves each still anchored at the root.
3. Peel. Remove the papery skin and any tough outer layer.
4. Place a half flat side down, root end pointing away from your knife hand.
5. Make vertical cuts. Slice down through the onion toward the root, spacing the cuts as wide as you want your dice, and stop just short of the root so the layers stay attached. Angle your knife slightly toward the centre as you work around the curve to keep the pieces even.
6. (Optional, for finer dice) Make one or two horizontal cuts parallel to the board, again stopping before the root.
7. Slice across. Now cut crosswise, perpendicular to your vertical cuts. Each slice releases a row of dice.
8. Discard the root once you reach it.

Getting the size right:

• Large dice — cuts about ½ inch apart.
• Medium dice — about ¼ inch.
• Fine dice / minced — about ⅛ inch, using the horizontal cuts in step 6.

How to stop crying: Cutting an onion releases a sulphur compound that irritates your eyes. What actually helps:

• Use a very sharp knife — less crushing means less irritant released.
• Chill the onion in the fridge or freezer for 15–30 minutes first.
• Cut near a running vent, fan, or open window to move the fumes away.
• Keep the root end intact as long as possible — it holds a high concentration of the compound.

Tips: Curl the fingers of your guiding hand into a "claw" so your knuckles guide the blade and your fingertips stay tucked back. Diced onion keeps in an airtight container in the fridge for a few days, or freezes well for cooking.