Learn how to make Caramelized Onions and then use them as a topping or stir them into dishes to elevate the flavor to a new level! They’re rich, sweet and savory, and truly a secret ingredient that makes every dish I use them in better. Plus they’re incredibly easy to make, you just need some time and a bit of patience.

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I love onions so much, I really can’t understand how anyone doesn’t! As seen in my onion boil recipe, I could just eat them seasoned and baked whole. And French onion soup makes a regular appearance on my dinner table. So so good. I think a lot of people who dislike them really just dislike raw onions and are missing out on dishes like caramelized onions. Cooking them low and slow helps release the natural sweetness and turns basic onions into a sweet but savory condiment. If you’re an onion lover like me, be prepared to eat these by the forkful!

Overhead view of a pot of caramelized onions

What’s in this Caramelized Onions recipe?

There are only 4 very basic ingredients needed to make this recipe and pretty standard kitchen items. You can find the exact measurements needed in the recipe card below.

Butter – I like to use unsalted butter so I can add salt separately. If you use salted butter, you’ll likely want to omit the extra salt.
Sweet onions – Really any onion can be used, but sweet onions are best for caramelizing because of their natural higher sugar content.
Granulated sugar – Yep, sugar. Just a pinch of sugar will actually help release the natural sugars in the onions while cooking. It also adds depth of flavor while not making them overly sweet.
Salt – Heightens the other flavors and balances out the sweetness.

Tips for Success

Slice thinly. The onions should all be sliced into very thin slices. Thicker slices will take longer to caramelize and may not cook all the way through.
Use a mandolin. While you can definitely slice the onions by hand, I like to use a mandolin. It ensures thin, even slices with less work.
Cook low and slow. Making caramelized onions is not a process that can be rushed. It takes time for the onions to caramelize and release their natural sugars which results in the best flavor. Increasing the heat to reduce the time will just result in burnt onions.
Stir regularly. I like to stir the onions every 5 minutes or so as they cook. This ensures none stick to the pan or burn and also that all of the onions are cooked evenly.
Decrease in volume. Onions shrink down significantly when cooked (like mushrooms and spinach!), so what looks like on ton in the beginning, will yield much less at the end.

A hand dipping a chip into caramelized onions

Ways To Use Caramelized Onions

I love adding these caramelized onions to so many things. Caramelized onion dip is a fun twist on classic French onion dip and they’re fantastic stirred into mac and cheese to make French onion mac and cheese. They’re perfect on a burger (like my Juicy Lucy burgers) and are a great way to add flavor to grilled cheese. I’ve also served them with crostini as an appetizer. Half of the time I just eat them by the forkful!

How To Store Leftovers

Fridge. Store leftover caramelized onions in an airtight container in the fridge. They’ll last for up to 5 days.
Freezer. These also freeze well. I like to portion them into ice cube trays so that I can reheat a small amount whenever I need them.
Reheat. Reheat the onions on the stovetop over low heat so they don’t scorch. You can also pop them in the microwave until warmed through.

I hope you love this delicious and easy recipe – be sure to give it a review below! Also don’t forget to follow Belly Full on TikTok, Instagram, Facebook, Pinterest, and YouTube!