Keep the onion root intact for uniform dice
By How To (/journals/how-to)
Keep the root end intact until the final cuts. That hinge holds every layer so the pieces stay uniform.
Before you start: a sharp chef's knife, a cutting board set on a damp cloth so it cannot slip, and one firm onion.
1: TRIM the stem end only while the root stays whole: lay the onion on its side and take a thin top disc with fingertips curled under.
The new face should sit flat with no rock. If it tips, shave one more thin slice until the board contact is steady.
2: HALVE straight down through the root: stand the onion on the flat face and slice from the stem scar through the root center.
Both halves should show matching layer depth. A thick side means the blade drifted—recenter and finish the line.
3: PEEL the skin from each half starting at the cut edge: pinch the paper layers and pull them back toward the root.
The flesh should look clean with no dry film left. Skin that clings needs a deeper lift from the stem edge.
4: SCORE parallel lines toward the root without cutting through it: claw-grip the half and space cuts about a quarter inch apart for medium dice.
Grooves should stop short and leave the root band solid. Layers that flop free mean the blade went too far—leave a thicker uncut heel.
5: CUT one or two level slits parallel to the board, stopping before the root: keep the blade flat at mid height.
The upper section should shift yet stay hinged at the root. If it drops free, ease off depth on the next pass.
6: DICE crosswise from the stem toward the root in the same spacing: let the root hold the stack, then discard the stub.
Pieces should read as even cubes on all sides. Long shards mean earlier gaps were uneven—match the quarter-inch rhythm next time.
The most common mistake
Slicing the root off first lets the layers collapse into uneven slabs. Leave the root whole until the last crosscuts so the stack stays put.
Pro tip
A sharp knife parts the flesh cleanly instead of crushing it, so cuts stay neat and your eyes sting less.
Say it every time
Trim halve peel score cut dice—root last