Home › Home & Kitchen › Kitchen & Dining › Cutlery & Knife Accessories › Chef's Knives How to Dice an Onion Published: July 9, 2026 · Updated: July 9, 2026
Photo: Krzysztof Puszczyński CC0 1.0 Source
Halve the onion pole to pole and peel, then lay a half flat and make horizontal and lengthwise cuts toward — but not through — the root, so it holds together; finally slice across and the dice fall away. Leaving the root end intact is the whole trick, and a sharp knife means fewer crushed cells and fewer tears.
Recommended Halve pole-to-pole, cut toward the intact root twice, then slice across — even dice, no slipping — A neat dice comes from using the onion's own root end as a handle that keeps the layers together until the last cut. Trim only the top, cut the onion in half from top to root, and peel — keeping the hairy root on holds each half in one piece. Set a half cut-side down, and with a sharp chef's knife make a few horizontal cuts parallel to the board toward the root without severing it, then several vertical cuts down through the layers, again stopping short of the root. Now slice straight across and uniform cubes drop off; the closer together your cuts, the finer the dice. Curl the fingers of your guiding hand back into a claw so the knife rides your knuckles safely. For less crying, chill the onion 15 minutes first, keep your knife sharp so it slices rather than crushes the cells that release the sting, and work near good airflow. The last stubborn root nub can be discarded or minced separately.
