Make perfect sauteed onions every single time with my amazing grilled onion hack! The perfect addition to so many meals, this post will teach you how to sauté onions with a quick and easy method. Plus, a secret ingredient!

What Makes This Recipe Great

It still blows my mind that onions, such a strong-tasting vegetable, can cook down into something so sweet and caramelized. The flavor is completely transformed, and you end up with tender, delicious onions! Sauteed onions are so versatile and delicious, and they go with just about everything!

I love onions grilled for burgers, pizzas, sandwiches, breakfast, and even on my salads, but they have to be cooked just right. The first few times I made them, it was a complete disaster. As in, the smoke detector went off, and I was left with a pan full of charred remnants of what used to be an onion.

So, to help you avoid the same mistakes, here is exactly how I make my sauteed onions recipe, grilled perfectly in my cast iron pan, every single time!

Ingredient Notes

All you need are four simple ingredients to make these caramelized onions:

ingredients to make grilled onions
  • Onions: You can use Vidalia onions (sweet), yellow onions, or red onions. Take your pick! The type of onion won’t change the process, just the flavor you’re going for. 

The rest of the ingredients are salt and butter, and my absolutely amazing hack is a little water. I know it sounds weird, but trust me, it’s the best hack and makes the caramelization process absolutely perfect!

Step-By-Step Instructions

step by step instructions on how to make the perfect caramelized onions
  1. Slice the onions like in the photo above (about 3/8″ thick). You can cut the onion in different ways, but I prefer them like this.
  2. Heat your cast iron skillet (or large skillet) over medium heat. Reduce to low heat if needed throughout this process. 
  3. Add the onion slices and butter, and sprinkle in the kosher salt. Then cook, stirring frequently, so they don’t stick to the bottom of the pan.
  4. Here is my secret to cooking onions: As soon as the sliced onions start to look a little dry, add a few tablespoons of water. This will prevent the onions from drying out and keep them juicy and cooking at an even temperature. The water will evaporate as it cooks, leaving you with perfectly juicy onions. I usually add water twice during the cooking process.
  5. Continue to saute onions uncovered until they are soft and golden brown—about 30 minutes.
  6. Serve as an easy side dish, as a part of an entree, or any meal that calls for perfect sauteed onions. They are multi-purpose and so delicious! 

My Amazing Grilled Onion Hack

WATER! As soon as the onions start to look a little dry, add a few tablespoons of water. This will prevent the onions from drying out and will keep them juicy and cooking at an even temperature.

pouring water into the pan while sauteeing onions

The water will evaporate as you are cooking the onions, leaving you with perfectly juicy onions grilled to absolute perfection. As you saute the onions, their natural sugars release into a beautiful, caramelized, sweet flavor.

Which Onions Are Best for Grilling?

This simple recipe works with yellow onions, white onions, red onions, sweet onions, and more! Basically, whatever flavor profile you’re looking for, choose that onion and grill it! No matter what, they’ll taste amazing!

  • Red Onion: great for steak, burgers, sandwiches, and salads!
  • Yellow Onion: milder in flavor, great with burgers, stir fry, fajitas, casseroles, and other Mexican-inspired dishes.
  • Sweet Onion/Vidalia Onion: a mild flavor with a hint of sweetness, great with pizza, pasta, and sauces.

Ways to Serve Grilled Onions

Some people eat sauteed onions by themselves with a pinch of salt and pepper and a splash of balsamic vinegar. Grilled onions are also great for any of your favorite dishes such as:

burgers

patty melt

salads

sandwiches

casseroles

dips

fajitas

stir-fry

sauces

chicken

pizza

steak dishes

pasta

soups

tacos

Expert Tips

  • Dairy Free/Vegan: If you need these sauteed onions to be dairy free, you can use coconut oil or olive oil for grilling onions in place of butter or ghee.
  • Whole30: Use ghee or coconut oil to keep these Whole30 friendly.
  • Storing: Store leftovers in an airtight container in the refrigerator for up to 5 days or frozen for up to 6 months. You can enjoy them cold out of the fridge or reheat them in the microwave or skillet.

Recipe FAQs

Is grilling onions keto-friendly?

Yes! Onions are super low in carbs and make for a great, flavorful addition to any keto-friendly meal. Sauteed onions grilled with butter makes the fat content higher, helping you reach your daily macros!

Can I freeze grilled onions?

Yes! They can be frozen for at least 6 months. You can enjoy them thawed and cold out of the fridge, or reheated in the microwave or skillet.

Are these grilled onions Whole30 compliant?

Use ghee or coconut oil to keep your onions grilled with Whole30-friendly ingredients.

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Grilled Onions Hack | How to Make Sautéed Onions

Make perfect sauteed onions every single time with my amazing grilled onion hack! The perfect addition to so many meals, this post will teach you how to sauté onions with a quick and easy method. Plus, a secret ingredient!
4.91 from 30 ratings

Ingredients 
 

  • 1 large yellow onion, sliced
  • 2 tablespoons butter or ghee
  • 1 teaspoon kosher salt
  • water

Equipment

Instructions 

  • Heat your cast iron skillet over medium heat.
  • Add the butter, onions and kosher salt. Cook stirring every few minutes.
  • As soon as the onions start to look a little dry, add in a few tablespoons of water. This will both prevent the onions from drying out and keep them juicy and cooking at an even temperature. The water will evaporate as it cooks, leaving you with perfectly juicy onions. I usually add water twice during the cooking process.
  • Continue to grill the onions uncovered until they are soft and golden brown. About 30 minutes.
  • Serve warm or cold.
  • See the Recipe Notes below for more tips, FAQ's and recipe substitutions.

Notes

Expert Tips

  • Dairy Free/Vegan: If you need these sauteed onions to be dairy free, you can use coconut oil or olive oil for grilling onions in place of butter or ghee.
  • Whole30: Use ghee or coconut oil to keep these Whole30 friendly.
  • Storing: Store leftovers in an airtight container in the refrigerator for up to 5 days or frozen for up to 6 months. You can enjoy them cold out of the fridge or reheat them in the microwave or skillet.
Calories: 236, Total Carbs: 7.5g, Protein: 1.1g, Fat: 23.1g, Fiber: 1.4g, Net Carbs: 6g
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