Seido's Pro Guide: How to Cut an Onion
Learning to cut onions the right way is a skill that will save you time and hassle in the kitchen while giving you greater control over the flavor of your food. A great chef’s knife from the Hageshi AUS10 Japanese Knife Set can help make cutting onions a breeze.
USE THE RIGHT TOOLS
The first step to cutting an onion is having the right tools. You’ll need a sharp blade and a stable cutting surface.
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THE BEST KNIVES FOR SLICING AN ONION
When you want to slice an onion, use a large, sharp, balanced knife like the Japanese Master Chef Knife. Many professional chefs slice, dice, and chop onions with stainless steel knives that are up to 10 inches long, but the size of the knife you choose is up to you. If you have a small grip, you may prefer a shorter knife that’s about 6 inches long.
The best knives are well balanced and make clean cuts. The handle should be made from a nonslip material like wood.
CHOOSE THE BEST CUTTING BOARD
A high-quality maple wood or bamboo cutting board makes the best surface for cutting onions. These boards are porous but durable, and the open grain will be gentle on your knives. Maple boards are good for cutting all kinds of vegetables, and they can be maintained with occasional sanding. They will be somewhat better for your knives than harder bamboo boards, which can dull your knives more quickly.
HOW TO SLICE AN ONION
Slicing onions properly takes a little finesse. Follow these tips, and you’ll be cutting onions like a pro.
STEP 1: TRIM THE ENDS
First, identify the papery stem end and hairy root end of the onion. Trim off about one-half inch of the stem end with your chef’s knife and set it aside. If you plan to slice or dice the onion, don’t trim the root. This way, the onion will keep its shape as you cut it.
STEP 2: SLICE THE ONION IN HALF
To slice the onion in half from root to stem, place the onion root-side up on your cutting board. Once the onion is stable, cut straight down through the root to slice the onion in half. Peel the onion and place the halves flat-side down on the cutting board.
STEP 3: CUT THE ONION VERTICALLY TO MAKE HALF-MOON SLICES
To make flat onion slices that look like half-moons, use this technique:
- Close your nondominant hand and grip the top of the onion, with your knuckles facing the stem end.
- Begin by laying one-half of the onion flat on the cutting board. Hold the onion with your nondominant hand, and make vertical slices from the curved side to the flat side. The greater the distance between slices, the thicker they will be.
HOW TO DICE AN ONION
Dicing an onion involves a few different steps, but the process is simple.
STEP 1: CUT FLAT LAYERS
Grip one of the onion halves and hold it firmly against the cutting board. With the blade of your knife parallel to the board and the edge facing the stem end, make several horizontal cuts through the side of the onion to create a stack of flat, one-quarter-inch layers. Stop each cut before you reach the root end.
STEP 2: CUT VERTICAL SLICES FROM ROOT TO STEM
While holding the cut layers of the onion in place, point the end of the knife towards its root and make several vertical, even one-quarter-inch slices from root to stem.
STEP 3: DICE THE ONION INTO CUBES
To dice the onion, turn it 90 degrees, then make a series of one-quarter-inch crosswise slices from the stem end to the root end to create one-quarter-inch cubes. Discard the root end.
HOW TO SLICE AN ONION INTO RINGS
Cutting an onion into rings is easy when you follow the steps below.
STEP 1: TRIM AND PEEL THE ONION
Cut off the stem end of the onion and peel off its outer layer of skin.
STEP 2: STABILIZE THE ONION ON THE CUTTING BOARD
Slice a thin section off the side of the onion. This creates a flat surface you can press against the board to stabilize your onion as you cut it.
STEP 3: SLICE THE ONION INTO RINGS
Hold the knife so that its edge is pointing down toward the cutting board. Turn the knife point 90 degrees away from the root. Starting at the stem end, cut through the onion to make round, even slices, and then separate the slices into rings.
HOW TO BRUNOISE AN ONION
When you brunoise an onion, you’ll need an extremely sharp knife like the Kiritsuke Damascus Chef Knife to create ultrafine pieces that make a beautiful garnish.
STEP 1: CUT AND PEEL THE ONION
Cut the onion in half, peel it, and hold the flat side against the cutting board.
STEP 2: MAKE VERTICAL, LENGTHWISE CUTS
Point the knife toward the root end. Make thin, even slices down through the onion without slicing through the root.
STEP 3: MAKE THIN, FLAT LAYERS
Hold the knife parallel to the board and make several horizontal cuts through the onion to create thin, flat layers.
STEP 4: BRUNOISE THE ONION
Turn the onion 90 degrees. Using a rocking motion, slice down into the onion across the strips you originally made to create finely cubed brunoise onion pieces around ⅛ by ⅛ by inches.
HOW TO SLICE AN ONION JULIENNE
When you cut an onion julienne, you’ll create thin, uniform strips that can be used to create a delicate flavor.
STEP 1: CUT AND PEEL THE ONION
Trim both ends of the onion and peel away the skin. Slice the onion in half and place the flat sides down on the board.
STEP 2: MAKE ANGLED CUTS THROUGH THE FIRST PART OF THE ONION
Grip one of the onion halves. You’ll be making radial slices toward the center of the onion by slightly changing the angle of the knife with each cut. To start, hold the blade at a 45-degree angle against the side of the onion with the edge of the blade turned toward the onion’s center. Begin slicing the onion into long, thin strips. As the knife moves away from you, gradually change the angle of the blade so that it’s perpendicular to the board when you reach the middle of the onion.
STEP 3: MAKE ANGLED CUTS THROUGH THE SECOND PART OF THE ONION
When you reach the middle of the onion, keep cutting, but angle the blade so that, when you finish, the blade will again be at a 45-degree angle and the edge of the knife pointed toward the center of the onion. At this point, you will have thin strips of onion that can easily be separated.
HOW TO QUARTER AN ONION
Quartering an onion is a very simple way to prepare it for stews and roasts.
STEP 1: TRIM AND PEEL THE ONION
Cut the stem end of the onion and peel away the skin.
STEP 2: SLICE THE ONION INTO QUARTERS
Keep the root end attached, and cut the onion in from root to stem. Cut each half vertically from root to stem to create quarters, then trim the root ends off each piece.
HOW TO AVOID CRYING WHEN CUTTING ONIONS
Here are two that we recommend to help you from crying when cutting onions.
1. USE A VERY SHARP KNIFE
If you want to avoid tears the easy way, make sure your chef’s knife is extremely sharp. Cutting with a sharp knife causes less bruising and tearing of the onion’s cells and releases less of the tear-causing enzyme into the air.
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2. BRIEFLY FREEZE THE ONION
Freezing an onion for about 10 minutes before cutting it will reduce the amount of enzyme that gets released without changing the onion’s flavor or texture.
Learn How To Cut an Onion With Seido Knives!
ELEVATE YOUR CUTTING SKILLS WITH SEIDO KNIVES
Learning to cut an onion properly may seem intimidating, but the results will be worth it. With a little practice and a great chef’s knife from Seido Knives, you’ll take your cooking to the next level in no time.
