Use this technique on garlic, shallots, tomatoes, etc. as well!
Make sure you keep your “holding hand” in a C shape. Use your nails to slightly dig into the onion to use as an anchor. Your knuckles will work as a guard… better to knick your knuckle than loose the tip of your finger. 🤷♂️
Cut off the part of the onion opposite the root.
Cut down through the root. Then peel of the outer skin.
Position onion, flat-side down and with root under your “holding hand” Slice vertically 6-8 times through the onion about 1/2″ width. Only cut about halfway to the root.
Now slice horizontally 2-4 times through the onion. Only go as far as your vertical cuts went.
Now slice through the onion perpendicular to your vertical cuts. Adjust the width of your cuts to your needs.
Rotate the onion so the root is facing up. On the round side of the onion repeat the vertical, horizontal, and perpendicular cuts.