These Caramelized Onion Mashed Potatoes are flavorful, decadent, and perfect for the holidays! They're loosely inspired by French onion soup and though the onions take a bit of time and patience to make, the dish is still really simple and easy to make.
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Why This Recipe Works
French onion soup inspired - If you love French onion soup, these mashed potatoes are perfect for you! The potatoes are creamy and flavorful with just the right amount of buttery caramelized onions.
Surprisingly easy - You might think that caramelizing onions is a long and complicated process but I promise you it's not! It does take about 30 minutes to make the onions but it doesn't take very much hands-on work. They just need patience and time to caramelize.
Perfect for the holidays - If there's a time of the year that's perfect to serve these mashed potatoes, it's fall and winter! They're great for Thanksgiving or Christmas if you want to change up your dinner from regular mashed potatoes.
Ingredients
- Potatoes - Both Russet and Yukon potatoes are a great choice. Russet are ideal because of their high starch content but both work really well.
- Onions - Yellow onions are my go-to for most things and something I always have in the kitchen so I recommend them. White onion also works if that's what you have.
- Butter and oil - I like using a combination of the two because butter adds flavor and the oil makes sure the butter doesn't burn.
- Milk - Any milk you'd normally use for mashed potatoes works here. I like using cashew milk to keep the dairy content low but regular milk works great too!
- Creme fraiche - This is optional, you can also use sour cream if preffered. Creme fraiche is a thicker version of sour cream with more fat content. It's less tangy, richer, and less prone to curdling.
- Fresh thyme - I like adding fresh herbs to add some flavor and freshness to balance out the decadent caramelized onions. I recommend thyme but rosemary or parsley also work great. Dried herbs can be used in a pinch.
Variations and Substitutions
- Make it vegan - You can use vegan sour cream instead of creme fraiche or just skip it altogether. I like using cashew milk as a dairy-free milk in savory dishes and it works really well in these potatoes. Butter can be substituted with vegan butter.
- White onion - I like yellow onion the best for caramelizing because that's just what I have most often but white onion works just as well.
- Herbs - If you don't have fresh thyme, you can add fresh oregano, rosemary, or parsley. If you don't have any fresh herbs, dried herbs work great too, you'll just need much less because they're more concentrated.
- Sour cream - You can use sour cream instead of creme fraiche if you prefer a more tangy flavor.
Step-by-Step Instructions
- Heat a large pan over medium-high heat. Add butter and oil.
- Once the butter is almost melted, add the sliced onions and 1 teaspoon sea salt, and toss.
- Stir the onions often in the first 5 minutes of cooking. They should start to slightly caramelize around 10 minutes.
- Add the fresh thyme and half of the apple cider at around 15 minutes of cooking and the rest at 20 minutes.
- Add a splash of water as needed if the onions are sticking too much and burning.
- Cook for a total of 30-35 minutes. The onions should have a deep golden brown color but shouldn’t be burned. Set aside.
- While the onions are cooking, start cooking the potatoes.
- Add diced potatoes to a large pot of water and season with 1 teaspoon of sea salt and caraway seeds (if using). Bring to a boil, lower the heat, and simmer for 15 minutes or until the potatoes are tender.
- Drain the potatoes and return them to the pot.
- Add creme fraiche and half of the milk. Mash the potatoes using a potato masher or a handheld mixer.
- Add more of the milk and keep mashing. Add more until you reach the desired consistency.
- Stir in most of the caramelized onions but leave a little bit for garnish.
- Serve the potatoes with more caramelized onions, fresh thyme, or melted butter.
Serving Suggestions
These mashed potatoes are a great side to serve at Thanksgiving or Christmas along with all the other classic dishes. It also goes great with any meat, chicken, or roasted veggies like broccoli, cauliflower, bell peppers, or green peas.
Storing
You can store leftover mashed potatoes in an airtight container in the fridge for 3-4 days.
To reheat them, add the potatoes to a medium saucepan with a splash of milk or water to make sure the potatoes don't stick. Warm them up over low-medium until heated through. Stir often to make sure they don't stick.
FAQs
No, there's no need. Some recipes call for sugar because it helps the onions caramelize quicker but all you need is to add water as needed and to have patience. I like adding apple cider when I have it. It adds natural sugar and a little bit of flavor to the potatoes.
You can store the caramelized onions in the fridge for 3-4 days in an airtight container if you don't use all of them for the mashed potatoes. You can use them in burgers, sandwiches, and on meat or veggies.
More Mashed Potatoes Recipes
If you love potatoes and are looking for even more mashed potato variations for the fall and winter, try some of the four recipes linked below! The roasted garlic mashed potatoes are my personal favorite! To see all the latest sides, head over to the Sides category page.
- Rosemary Mashed Potatoes
- Roasted Garlic Mashed Potatoes
- Mashed Potatoes with Caraway Seeds
- Savory Mashed Sweet Potatoes
📖 Recipe
Caramelized Onion Mashed Potatoes
- Prep Time: 15 minutes
- Cook Time: 35 minutes
- Total Time: 50 minutes
- Yield: 2-4 1x
- Category: Sides
- Method: Stovetop
- Cuisine: American
- Diet: Vegetarian
Description
These Caramelized Onion Mashed Potatoes inspired by french onion soup are creamy, delicious, easy to make, and perfect for Thanksgiving!
Ingredients
- 2 tbsp butter
- 1 tbsp avocado oil (or other cooking oil)
- 2 large yellow or white onions, peeled and thinly sliced
- 2 tsp sea salt, divided
- 1 tsp fresh thyme
- ¼ cup apple cider (NOT apple cider vinegar)
- 1000g Yukon or russet potatoes, peeled and largely diced
- 1 tsp caraway seeds (optional)
- ½ cup creme fraiche
- 1 cup milk, divided (I use cashew milk)
Instructions
- Heat a large pan over medium-high heat. Add butter and oil.
- Once the butter is almost melted, add the sliced onions and 1 teaspoon sea salt, and toss.
- Stir the onions often in the first 5 minutes of cooking. They should start to slightly caramelize around 10 minutes. Add the fresh thyme and half of the apple cider at around 15 minutes of cooking and the rest at 20 minutes. Add a splash of water as needed if the onions are sticking too much and burning.
- Cook for a total of 30-35 minutes. The onions should have a deep golden brown color but shouldn’t be burned. Set aside.
- While the onions are cooking, start cooking the potatoes.
- Add diced potatoes to a large pot of water and season with 1 teaspoon sea salt and caraway seeds (if using). Bring to a boil, lower the heat, and simmer for 15 minutes or until the potatoes are tender.
- Drain the potatoes and return them to the pot.
- Add creme fraiche and ½ of milk. Mash the potatoes using a potato masher or a handheld mixer.
- Add more milk and keep mashing. Add more until you reach the desired consistency.
- Stir in most of the caramelized onions but leave a little bit for garnish.
- Serve the potatoes with more caramelized onions, fresh thyme, or melted butter.
Notes
Butter: The caramelized onions already have a decent amount of butter and oil in them and the creme fraiche is heavier than regular cream so I usually skip adding butter on top of the potatoes as I feel like they don’t need it but you totally can if you want!
Storing: Store any leftovers in an airtight container in the fridge for 3-4 days.
Reheating: Reheat the potatoes in a medium saucepan on the stove with a splash of milk or water until heated through.
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Gloria says
This is my kind of recipe. Carmelized onions are so delicious. Adding them to mashed potatoes is over the top fantastic. The perfect side dish, but I could make a meal on these alone.
Marta says
These are some of the best mashed potatoes I've had in a long time! The caramelization on those onions really makes a difference!
Bernice says
This dish is the ultimate comfort food. I can't get past how well the creamy mashed potatoes are with the caramelized onions. Funny though, as I was caramelizing the onions my husband came home and said 'dinner smells great'! I always think that's so funny... do you think I could get away with feeding him caramelized onions for dinner?
Sean says
I loved caramelized onions and I had not thought to put them with mashed potatoes. These were so good I need them in my life weekly.
Sarah James says
What an inspired idea, my family loves caramelised onions. Saving this recipe to try at Christmas.
Tammy says
I love this idea! I would never have thought of mixing in caramelized onions into my mashed potatoes but that's a winning combo and looks soo good! Cannot wait to give it a try!
Jenny says
I was skeptical about the caramelized onions before I tried them with the mashed potatoes. Though it would be too much. Well, I was so wrong, these were spectacular! Thanks so much for the idea and recipe. We had them with Greek style pork chops and there were no leftovers.
Jacqueline Debono says
Add caramelized onions to mashed potatoes is a genius idea. I've never been a fan of garlic mashed potatoes. I much prefer the potatoes with onions. This recipe is now a keeper.
Erin says
These potatoes were delicious! So easy, too. I'm going to make them for Thanksgiving!
Sandhya Ramakrishnan says
That caramelized onion topping added so much more flavor to the mashed potatoes. I love caramelized onions and this is one of the recipes that I am always going to use it in. This is definitely going to be in our holiday menu this year.