What You’ll Need
To cut onions properly, a few basics are essential. First up, choose the right knife. Start peeling with a paring knife, then switch to a chef’s knife for most of the cutting, slicing, and chopping. Make sure your knife is sharp—it makes the job easier and safer. Also, use a stable, roomy cutting board so you can work comfortably.
These basic cutting techniques work for all onion types—whether purple, red, or white.
No matter how you want to cut your onion, the prep steps are the same:
- Trim off the stem end.
- Peel off the skin by holding it between your thumb and a sharp knife blade, or simply peel it with your fingers.
- Then, cut the onion according to your recipe.
How to Slice Onions
Sliced onions are a staple in many dishes, from roasts to salads. Follow these steps for perfect slices:
- Cut the onion in half through the root.
- Use the tip of your knife to wedge around the root and remove it.
- Slice straight down in smooth motions across the onion half on your cutting board.
- When the pieces get too narrow to stand, turn the onion on its side and finish slicing.
How to Chop and Dice Onions
Finely chopped or diced onions are a go-to for soups, stews, and chilis. Here’s how to prep them:
- Start by cutting the onion in half through the root. Place one half flat-side down on your cutting board.
- Slice lengthwise at even intervals, being careful not to cut through the root end.
- Next, slice horizontally toward the root, keeping even spacing.
- Finally, cut straight down across the onion to create evenly sized pieces.
The process for dicing is the same—just make your cuts closer together for smaller cubes.
How to Cut Onion Wedges
Onion wedges are easy to make and popular in skillet recipes and roasted dishes. Just follow these two steps:
- Keep the root end intact and angle your knife toward the center of the onion.
- Slice through the onion several times. The small root piece helps keep the wedges together while cooking.
