Golden and bubbly hot caramelized onion dip. The sweet, jammy caramelized onions combined with four different types of cheeses makes the most delicious dip! Caramelize the onions in a pan and then let everything cook together in the slow cooker or the oven. Top it with a little shredded gruyere, and the crowd will go WILD!

hot caramelized onion dip on marble with crostini

Hot caramelized onion dip comin’ attacha! Open wide!

This is undoubtedly my most requested dip recipe from family and friends. 

And it’s easy to see why. Golden caramelized onions that I left hanging around on the stove until they were just tender and golden brown. Then comes all the creamy elements of the dip that we literally stir together in our slow cooker and pop a lid on. That’s it. 

Crunchy bread, hot dip, sweet onions, and all the creaminess. It’s perfection.

It’s pretty safe to say I have a borderline inappropriate relationship with party foods. Not in the sense that I want to eat all of them at once by myself in a closet somewhere. But in the way that I want to make them every time someone comes over. And not just make them, make them the main meal. Forget dinner; let’s pig out on hot caramelized onion dip, firecracker meatballs, pastry swirls, and hot honey cheese balls instead. That’s totally normal, right? 

I digress, but this dip would undoubtedly be the star of the show if you served it at a Christmas party or for New Years Eve or even a housewarming or for book club! Trust me, it was the first thing to disappear at our last housewarming party!

My task for you —

Make this dip.
Serve this dip.
Make everyone happy.

It’s that simple.

gruyere crusted onion dip on marble with toasted bread
@littlespicejar Caramelized Onio Dip! And yes, you can caramelize the onions a day or two ahead! Full recipe linked in my profile and on Search the web for “little spice jar jammy onion dip” #caramelizedonions #oniondip #frenchoniondip #chipsanddip #caramelizedoniondip #caramelizedonion #oniondiprecipe #homemadedip #frenchonion ♬ Romantique – Brigitte Bardot

Ingredients for hot caramelized onion dip:

  • Onions: I like to use yellowonions for this recipe that I slice very thinly and saute. You can also use sweet onions and cut back on the sugar if you want them to melt right into the dip. I like the little laces of onion strings, so I opt for yellowonions for this recipe.
  • Butter and Oil: A small knob of butter and a glug of oil help caramelize and sweat down the onions in a cast iron skillet.
  • Seasonings and Herbs: You’ll need some fresh thyme, onion powder, black pepper, and red pepper flakes for this recipe. All of these ingredients are added to enhance the other recipes in this dip.
  • Granulated Sugar: Helps develop a little more color on the onions and makes the sweetness of the onions more promenient.
  • Balsamic Vinegar: Is my secret ingredient to caramelized onions. The acid from the vinegar helps balance the sweetness and it just cuts through some of the richness from the creamier onion dip ingredients.
  • Garlic: no explanation needed here! Adds just a hint of garlicky flavor.
  • Cheeses: You’ll need cream cheese, parmesan cheese, diced brie, and shredded gruyere cheese. I’ve made this dip a ton over the years, so if you aren’t a fan of brie or want to make the dip a little lighter, feel free to swap the brie for another 4 ounces of cream cheese.
  • Sour Cream: Adds creaminess to the dip. I don’t suggest swapping this with greek yogurt!
  • Mayonnaise: Just like my hot spinach and artichoke dip, the sour cream and mayo are the creamy elements that make the base of this dip.
  • Milk: Helps thin out all the other ingredients a little bit!
  • Serving suggestions: Use chips, a slice dup baguette to make crostini, bagel chips would be a fine choice too!
caramelized onions in cast iron and dip ingredients in slow cooker

How to make golden bubbly caramelized onion dip

  1. Start with the onions. Add the butter and oil to a cast iron pan and heat over medium heat. When the butter melts, sweat the onions for a few minutes until they start to shrink back. Then season the onion mixture with thyme, sugar, and kosher salt. Cook the onions for 25-40 minutes or until they are a deep golden brown color. If you think they’re done, give them another few minutes to make sure! This is the step that adds most of the flavor – so take your time here! Then season with balsamic and cook for a few seconds before removing the onions from the heat.
  2.  Cook it in the slow cooker.Fold together all the ingredients except the brie and the gruyere in the bowl of a slow cooker sprayed with cooking spray. This makes clean up much, much easier. Cook this for 2 hours, then stir in the brie and top with the shredded gruyere. Cover and cook for another 20-25 minutes or until the gruyere on top melts. Keep it mind, the gruyere in the slow cooker won’t get bubbly and golden. But I’ve included ways to do that in the oven.
  3. Or bake it in the oven. Once you’ve caramelized the onions, combine all of the remaining dip ingredients in a medium bowl except for the shredded. gruyere. Dump the dip into a baking dish sprayed with cookign spray and bake in the oven for 45-50 minutes or until all the dip heats and cooks through. Broil for the last 30-60 seconds until the gruyere is golden and bubbly.
bubbly onion dip in slow cooker

FAQs about hot caramelized onion dip

Is it better to caramelize onions with butter or olive oil?

I like to use a combination of the two ingredients. Butter provides the flavor while oil provides the high cooking temps.

Should you add sugar when caramelizing onions?

There is a lot of debate on this. Adding sugar to caramelize onions helps boost the natural sweetness of the onion. I think you could omit the sugar if you use sweet onions (such as Vidalia,) as those contain a higher sugar content as is. For yellow onions, I definitely like to add a bit.

Why are my caramelized onions burning and not caramelizing?

You’ve got the burner turned up too high. To caramelize onions properly, you want to use a cast iron skillet with the heat bouncing between medium and medium-low. If they’re browning too fast, turn the heat down, add a tablespoon of water and let them go low and slow. If they’re already burnt, toss them! They won’t do the dip any good.

How did you get the cheese to brown in the slow cooker?

For some of the pictures in this post, I used a kitchen torch, however, I do not suggest doing this unless you are VERY comfortable doing so. Please use at your own risk.

What if my dip has a pool of oil on top?

This is completely normal! It can happen because of all the high-fat cheeses we’re using (gruyere and brie mostly.) I just lay a paper towel on top and let it absorb all the oil and then pop it back under the broiler or put it out for serving.

bread dipped into gruyere onion dip

If you like this recipe, you might also like:

toasted bread in dip

Original Recipe shared Dec 2015. Updated with new image, post, and updated recipe instructions Dec 2022.

Yield: serves 10-12

Jammy Hot Caramelized Onion Dip with Gruyere

Prep Time 10 minutes
Cook Time 1 hour 30 minutes
Total Time 1 hour 40 minutes

Golden and bubbly hot caramelized onion dip. The sweet, jammy caramelized onions combined with four different types of cheeses makes the most delicious dip! Caramelize the onions in a pan and then let everything cook together in the slow cooker or the oven. Top it with a little shredded gruyere, and the crowd will go WILD!

hot caramelized onion dip on marble with crostini


  • 2 large onions, halved and thinly sliced
  • 1 tablespoon EACH: butter AND oil (such as avocado)
  • ½ teaspoon EACH: fresh thyme AND onion powder
  • 2 teaspoons granulated sugar
  • 1½ teaspoon balsamic vinegar
  • 4 ounces cream cheese, softened
  • ½ cup EACH: sour cream AND mayonnaise
  • ¾ cup milk
  • 1 tablespoon minced garlic
  • ½ teaspoon red pepper flakes
  • ¼ teaspoon black pepper
  • ¼ cup grated parmesan cheese
  • 4 ounces of brie, diced (see notes for sub)
  • 1 cup shredded gruyere (see notes for sub)
  • prepared crostini, for serving


    1. CARAMELIZE: Heat the oil and butter in a large cast iron skillet over medium heat. Add the onions and let sauté for 5 minutes, stirring frequently. Add the thyme, sugar, and ¼ teaspoon kosher salt and continue to cook for a minimum of 25 and up to 45 minutes on medium-low heat. Stir the onions every 5 minutes so they caramelize evenly. If, at any point, the onions are caramelizing too fast, turn the heat down to low. When the onions are soft and golden, add the balsamic, and allow the onions to soak it in. Remove from heat.
    2. TOSS IT IN: Spray the inside of your slow cooker with cooking spray to keep the dip from sticking. Add the onions and all the remaining ingredients except the brie and gruyère to the slow cooker.
    3. SLOW COOK: Cover and cook for 2 hours on the high setting. Check and stir once or twice, if possible. Add diced brie cheese and stir to combine. Top with shredded Gruyère, cover, and continue cooking for another 20-25 minutes or until the Gruyère melts. Keep in mind, the cheese won’t form a brown crust in the slow cooker. It will melt and become stringy, though. See below for broiling instructions.
    4. BUBBLY TOP: For a bubbly top, add the brie and cook in the slow cooker for 20 minutes. Then transfer the dip to a 2-quart baking dish sprayed with cooking spray. Top with Gruyère and let the cheese melt under the broiler for a few minutes. Serve warm with crostini slices or crackers.
    5. OR OVEN: Complete step 1. Add all the ingredients except the gruyere to a bowl and stir to combine. Dump the ingredients out into a 2-quart baking dish. Top with the shredded gruyere and bake in an oven preheated to 375ºF for 45-50 minutes. Check the dip to ensure it’s not browning too much at any point. Broil for the last 45-60 seconds to get that golden crust on top!


    * The recipe can easily be doubled in a 3-quart slow cooker or tripled in a large-sized crockpot. Cooking time may vary for larger batches.
    * caramelized onions: can be done up to 48 hours in advance.
    * gruyere: can be replaced with shredded white cheddar or provolone cheese for a more economical option!
    * brie: can be replaced with another 4 ounces of cream cheese.
    * make ahead: cook the dip without the gruyere in the slow cooker. Transfer to a baking dish, cover it, and refrigerate for up to 48 hours before serving. Remove from the refrigerator 1 hour before baking. Top with gruyere and bake at 350ºF covered for30-40 minutes or until everything heats through and the cheese on top melts.

Have you made this recipe?

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