How to slice an onion using the knuckle guide (vertical slices)
Rest the knife against your knuckles and slide your fingers back gradually to slice onions evenly and safely.
Place the cut side of the onion down for stability and keep a firm grip. Rest the knife blade against your knuckles as a guide, then make fine, even slices while gradually sliding your fingers backward as the knife approaches.
The short version
- Keep the onion stable (cut-side down)
- Use knuckles as a blade guide
- Move fingers back gradually as you slice
What you need
- knifeSharp knife recommended
- cutting board
How to do it
- 1
Set the onion half cut-side down so it sits flat on the board.
A flat base prevents wobbling.
Watch this step - 2
Hold the onion with a firm grip, keeping fingertips tucked back.
Keep all fingers in place and stable.
Watch this step - 3
Rest the knife against your knuckles to guide the blade.
This helps avoid slicing your fingers.
Watch this step - 4
Slice gradually and evenly, sliding your guiding hand backward as you go.
Aim for thin or thick slices as needed.
Watch this step
What goes wrong
Letting the onion wobble while slicing
Keep the cut surface on the board and maintain a firm grip
Not using a guide hand and cutting unevenly or unsafely
Rest the blade against your knuckles and tuck fingertips back
Why it works
Using knuckles as a guide helps control blade position and protects fingertips while keeping slice thickness consistent.
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