How to Cut, Slice & Dice an Onion

Welcome back to another AK Back to Basics tutorial! I know that you all come from different levels of cooking experience, which I love. Some cooking techniques that are second nature to some of you might be brand new to others. That’s why I decided to launch the Back to Basics series — so that wherever you are in your food & cooking journey you always have useful tips and tricks for gaining confidence in the kitchen.

In this tutorial, I’m showing you step-by-step instructions not only on how to cut an onion but also how to easily slice and dice it. It may sound simple, but I’ve even seen Abra (my resident veggie chopper) almost slice her fingers off when dicing onions for our recipes. I learned this trick from my mom and it’s truly life-changing, just ask Abra.

I also have a super helpful video that will show you exactly how to do it. Let’s get to it!

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How to cut an onion: 3 different ways

Method 1: make onion rings

Cutting an onion into rings is great for topping burgers and, of course, making baked or fried onion rings!

Step 1: lay the onion on a sturdy cutting board (use the code ‘ambitiouskitchen15’ for 15% off of our favorite brand!) on its side and use a sharp knife to chop off the stem that does not have the root on it. This side will typically be the “pointier” side of the onion.

Step 2: peel the onion and flip it on its side.

Step 3: carefully slice the whole onion into equal-sized rings.

Step 4: separate the rings and add them to burgers or put them directly on the grill!

Method 2: make slices

Use this method for sandwiches, salads and caramelizing.

Step 1: start with step 1 of the first method so that your onion does not have the stem on it.

Step 2: flip your onion over onto the freshly chopped side so that it’s flat and doesn’t roll around.

Step 3: cut your onion straight down the middle, through the root.

Step 4: peel off the skin on both halves.

Step 5: lay your onion halves flat and carefully cut each half into slices starting at the stem end that you previously removed.

Method 3: dice your onion

This method is great for cooking onion in savory recipes as you can make super small diced pieces or larger chunks. It’s also the perfect method for salsas and dips!

Step 1: follow steps 1-3 above for cutting an onion into slices.

Step 2: lay your onion halves flat and make small cuts with your knife towards the root side about 3/4 of the way to the root. Make these cuts about 1/4 inch apart.

*Note: you can make these cuts smaller and closer together if you want a finer dice, or larger if you want larger chunks.

Step 3: flip your knife so that it’s parallel to the cutting board, hold onto the top of your onion with your other hand, and carefully slice your onion through the middle of the onion by gently gliding it. Slice it about halfway through towards the root.

Step 4: finally, dice your onion by slicing it from top to bottom. You can dice it finely or into larger chunks depending on how close together you slice. With the last 1/4 of the onion, you can just chop it regularly — discarding the root. Then repeat with the second half.

Watch the video tutorial on how to cut an onion:

Ways to use freshly sliced and diced onion

• Use sliced onion in this Homemade Roasted Tomato Basil Soup this Vegan Pasta Primavera and this Goat Cheese & Spinach Stuffed Chicken Breast with Caramelized Onions + Mushrooms
• Top these juicy Moroccan-Spiced Turkey Burgers and these Ultimate Vegan Black Bean Burgers with onion rings
• Dice up some onion for my Brown Butter Goat Cheese Grilled Veggie Orzo and this Fresh Mango Salsa

How to store freshly chopped onion

Store your freshly chopped or sliced onion in an airtight container or bag in the refrigerator for up to 7-10 days.

More how-to guides and tutorials

• How to Cut a Pineapple (3 different ways!)
• Tony’s Ridiculously Easy Homemade Salsa
• How to Grill Delicious Vegetables (4 different ways!)
• How to Cook the Perfect Chicken Breast (4 different ways!)
• Easy Homemade Taco Seasoning

Get all of our easy how-to guides here!

I hope you guys loved this easy tutorial on how to cut an onion! If you try out this method be sure to leave a comment below and let me know how you liked it. Remember, practice makes perfect! Sign up for the AK VIP List to get more Back to Basics posts straight to your inbox.

How to Cut, Slice & Dice an Onion

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Prep Time 5 minutes minutes

Total Time 5 minutes minutes

Cutting, slicing and dicing an onion into equal-sized pieces can be tricky, but it's easier than you think with a few quick tips! In this step-by-step tutorial, you'll learn how to peel, cut, slice and dice an onion for cooking, topping salads and burgers, and more.

Ingredients

• 1 onion

Instructions

• Lay the onion on its side and use a sharp knife to chop off the stem of that does not have the root on it. This side will typically be the “pointier” side of the onion.
• FOR RINGS

  Peel the onion and flip it on its side. Carefully slice the whole onion into equal-sized rings.

  Separate the rings and add them to burgers or put them on the grill!
• FOR SLICES

  After cutting the stem off of the onion, flip your onion over onto the freshly chopped side so that it’s flat and doesn’t roll around.

  Cut your onion straight down the middle, through the root.

  Peel off the skin on both sides.

  Lie your onion halves flat and carefully cut each half into slices starting at the stem end that you previously removed.
• FOR CHUNKS AND DICED PIECES

  Follow steps 1-3 for slicing an onion.

  Lay your onion halves flat, and make small cuts with your knife towards the root side about 3/4 of the way to the root. Make these marks about 1/4 inch apart. *Note: you can make these cuts smaller and closer together if you want a finer dice, or larger if you want larger chunks.

  Flip your knife so that it’s parallel to the cutting board, hold onto the top of your onion with your other hand, and carefully slice your onion through the middle of the onion by gently gliding it. Slice it about halfway through towards the root.

  Finally, dice your onion by slicing it from top to bottom. You can dice it finely or into larger chunks depending on how close together you slice.

  With the last 1/4 of your onion feel free to just chop it regularly – discarding the root.

  Repeat with your second half!

Recipe Notes

To store: store your freshly chopped or sliced onion in an airtight container in the refrigerator for up to 7-10 days.

Method by: Monique Volz // Ambitious Kitchen | Photography by: Eat Love Eats

This post was originally published on October 24, 2018, and republished with new instructions & photos on August 15, 2021.