If you’re looking for a side dish that takes classic mashed potatoes up a notch and makes your dinner table feel downright fancy, you’ve got to try this French Onion Mashed Potatoes Recipe. I absolutely love how the sweet, deeply caramelized onions blend with creamy potatoes and melted Gruyère, creating a flavor combo that’s comforting yet sophisticated. Trust me, once you try it, you’ll want to make it again and again!
Why You’ll Love This Recipe
- Rich, Complex Flavor: The caramelized onions add a deep, sweet umami taste that transforms regular mashed potatoes into something incredible.
- Creamy, Buttery Texture: Using plenty of butter, heavy cream, and Gruyère cheese gives the dish luxurious creaminess that everyone adores.
- Comfort Food with a Twist: It feels classic and cozy but has a gourmet touch that impresses guests and family alike.
- Versatile for Any Occasion: Whether it’s a weeknight dinner or a holiday feast, this recipe always fits right in.
Ingredients You’ll Need
The magic here happens by layering simple ingredients that bring out the best flavors in each other. I like to choose sweet onions for caramelizing because they mellow out beautifully, and Yukon Gold potatoes create that perfect creamy texture without getting gluey.
- Caramelized onions: Using thinly sliced sweet onions helps achieve that lovely golden color and natural sweetness during slow cooking.
- Unsalted butter: I always recommend unsalted so you can control the seasoning perfectly.
- Kosher salt: Essential for seasoning both the onions and the potatoes well without overpowering.
- Potatoes: Russet or Yukon Gold are your best bet; Russet for fluffy texture, Yukon Gold for creamier, buttery results.
- Heavy whipping cream: Warming this with butter before adding keeps the potatoes creamy and rich.
- Gruyère cheese: Freshly grated for a nutty, melty touch that elevates the whole dish.
- Freshly ground black pepper: Just a pinch to finish off and balance the flavors.
Variations
One of the things I love most about this French Onion Mashed Potatoes Recipe is how easily you can tweak it to your liking. Whether you’re avoiding dairy or want a bit more crunch, you can adjust it to fit your meal perfectly.
- Dairy-Free Variation: Replace butter and cream with olive oil and coconut milk or your favorite plant-based alternatives—I tried this for a friend, and it turned out surprisingly delicious!
- Herb Infusion: Stir in some fresh thyme or rosemary during the caramelization step for an herbaceous twist.
- Extra Cheesy: Swap Gruyère for sharp aged cheddar or add a sprinkle of Parmesan on top for a bolder flavor.
- Crispy Onion Topping: Fry some thinly sliced onions separately and sprinkle over the mashed potatoes just before serving for added texture.
How to Make French Onion Mashed Potatoes Recipe
Step 1: Slowly Caramelize Your Onions for That Deep Flavor
Heat 6 tablespoons of unsalted butter in a skillet over medium-low heat, then toss in the thinly sliced sweet onions with a generous pinch of kosher salt. I like to stir them every few minutes to make sure they don’t stick or burn. After about 10 to 15 minutes, turn the heat down to low—we want slow, patient cooking so the onions turn golden and sweet without burning. Expect this to take about 45 to 60 minutes. It’s a bit of a slow dance, but I promise—it’s worth the wait!
Step 2: Prep and Cook Your Potatoes Just Right
I always recommend prepping your potatoes ahead if you can—peel, chop, and soak them in cold water to remove excess starch, storing in the fridge up to 18 hours before cooking. When you’re ready, drain and put the chunks in a pot with cold, salted water. Bring it to a boil over medium heat, then simmer until fork-tender, about 12 to 15 minutes. Watch them closely—if your pieces are smaller, check at 10 minutes to avoid overcooking.
Step 3: Warm Your Butter and Cream While Potatoes Boil
While the potatoes are cooking, heat 12 tablespoons of butter with 1½ cups of heavy whipping cream over medium-low heat. This warm mixture helps your mashed potatoes stay creamy and ultra smooth—don’t skip this step! It’s one of my small secrets for rich results every time.
Step 4: Mash, Mix, and Fold in That Wonderful Onion Flavor
Drain your potatoes well and get ready to mash. I use a potato masher first to get the consistency I like. Then, mix in half of your warm butter and cream, plus 1 teaspoon salt, tasting as you go. If you like ultra-smooth potatoes, a hand mixer set to low helps, but be careful not to overmix or they’ll turn gummy. Finally, stir in the grated Gruyère and the other half of your caramelized onions, allowing the cheese to melt slowly into the mixture. Season with extra salt and pepper as needed—tasting frequently is key here.
Step 5: Serve with Style and Extra Onion Love
Spoon the creamy potatoes onto your serving dish and top with the remaining caramelized onions. The contrast in texture and that gorgeous onion aroma will have everyone coming back for seconds!
Pro Tips for Making French Onion Mashed Potatoes Recipe
- Go Low and Slow with Onions: Patience here makes all the difference. Rushing caramelization results in bitter onions, so keep the heat low.
- Soak Potatoes to Remove Starch: I learned this trick to get fluffy potatoes instead of gluey ones—soaking before cooking helps immensely.
- Warm Your Butter and Cream: Adding warm dairy to the potatoes keeps them creamy and blends beautifully, no lumps.
- Avoid Overmixing: Excessive mixing makes potatoes gummy. Use gentle mashing or a low-speed mixer.
How to Serve French Onion Mashed Potatoes Recipe
Garnishes
I always finish with a sprinkle of fresh chives or parsley for color and a little fresh bite that cuts through the richness. Sometimes a small grating of nutmeg or extra cracked black pepper on top adds a lovely aroma too. And if you’re feeling indulgent, an extra handful of crispy fried onions is pure heaven.
Side Dishes
This French Onion Mashed Potatoes Recipe pairs beautifully with roasted chicken, grilled steak, or even a simple green vegetable like sautéed green beans or roasted Brussels sprouts. My family goes crazy when I serve this alongside a garlic-rubbed roast beef—it’s just perfect!
Creative Ways to Present
For special occasions, I sometimes pipe the mashed potatoes into little rosettes on a baking sheet and pop them under the broiler until golden on top, adding caramelized onion bits before serving. It looks fancy but is surprisingly easy to pull off!
Make Ahead and Storage
Storing Leftovers
I store leftovers in an airtight container in the fridge, where they keep well for up to 3 days. To keep the texture smooth, I recommend gently reheating and adding a splash of cream or milk to loosen them up before serving.
Freezing
I used to struggle freezing mashed potatoes because they often got dry or grainy. With this recipe’s high butter and cream content, I found it freezes quite well if you cool them fully and seal them tightly. Defrost overnight in the fridge before reheating gently.
Reheating
When reheating, use a low heat on the stovetop or in the microwave in short bursts, stirring often. If the potatoes feel thick, stir in a bit of warm cream or milk to reach that perfect creamy texture again.
FAQs
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Can I use regular yellow onions instead of sweet onions for the caramelized onions?
Absolutely! Yellow onions work well for caramelizing and will offer a slightly sharper taste compared to sweet onions, but the slow cooking process mellows them nicely. Just be sure to caramelize slowly over low heat to avoid bitterness.
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What is the best potato to use in this French Onion Mashed Potatoes Recipe?
Russet potatoes are great for fluffy, light mashed potatoes, while Yukon Golds bring a naturally buttery and creamier texture. I personally prefer Yukon Golds for this recipe because they complement the rich, cheesy flavors perfectly.
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Can I make the caramelized onions ahead of time?
Yes, caramelized onions keep beautifully in the fridge for up to a week. Making them in advance saves you time on the day you prepare the mashed potatoes. Just warm them a bit before folding into the potatoes for best flavor.
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Is it okay to use a hand mixer to mash the potatoes?
You can, but use it on a low speed and only briefly. Overmixing with an electric mixer can make mashed potatoes gluey or gummy, so I suggest mashing by hand first and then smoothing out with the mixer just a little if you want extra creaminess.
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How do I adjust the salt in this recipe?
Salt amounts can vary depending on your taste and the saltiness of your butter or cheese. I always recommend adding salt gradually, tasting as you go, especially after adding the caramelized onions and cheese, to avoid oversalting. It’s easier to add more than to fix too much salt.
Final Thoughts
This French Onion Mashed Potatoes Recipe is one of those dishes that feels like an indulgent hug on a plate. I remember making it for my family the first time and getting so many compliments that it quickly became a holiday staple. The blend of creamy potatoes, sweet onions, and melted Gruyère creates a comforting yet elegant dish that’s perfect any time you want to impress without a ton of fuss. Give it a go—I promise it’ll become one of your favorite mashed potato recipes too!
Print
French Onion Mashed Potatoes Recipe
- Prep Time: 1 hour 10 minutes
- Cook Time: 20 minutes
- Total Time: 1 hour 30 minutes
- Yield: 8 to 10 servings 1x
- Category: Side Dish
- Method: Stovetop
- Cuisine: French-American
Description
This French Onion Mashed Potatoes recipe combines creamy, buttery mashed potatoes with rich caramelized onions and melted Gruyere cheese for a decadent side dish perfect for family dinners or special occasions. The slow-cooked onions add a deep, sweet flavor that complements the smooth mashed potatoes wonderfully.
Ingredients
Caramelized Onions
- 6 tablespoons Simply Nature Organic Unsalted Butter
- 4 sweet onions, thinly sliced
- Kosher salt, to taste
Potatoes
- 5 pounds russet or Yukon gold potatoes, washed and peeled
- 12 tablespoons Simply Nature Organic Unsalted Butter
- 1 1/2 cups Friendly Farms Heavy Whipping Cream
- 8 ounces Emporium Selection Le Gruyere Cheese, freshly grated
- 1 to 2 teaspoons salt
- Freshly ground black pepper, to taste
Instructions
- Caramelize the Onions: Heat 6 tablespoons of butter in a skillet over medium-low heat. Add the thinly sliced onions along with a generous pinch of kosher salt. Cook, stirring often, for 10 minutes until the onions begin to soften. Reduce heat to low and continue cooking, stirring occasionally, for 45 to 60 more minutes until the onions are deeply golden and caramelized. Adjust cooking time for desired caramelization.
- Prepare Potatoes: Wash, peel, and cut potatoes into uniform chunks, either halves or quarters depending on size to ensure even cooking. For advance prep, soak chopped potatoes in cold ice water in the fridge for 12 to 18 hours. Place potatoes in a large pot with cold water and a pinch of salt over medium heat. Bring to a boil and cook until fork tender, about 12 to 15 minutes. Smaller pieces may take about 10 minutes.
- Warm Butter and Cream: While potatoes boil, warm 12 tablespoons butter and 1 ½ cups heavy cream together in a saucepan over medium-low heat until fully warmed through.
- Mash Potatoes: Drain potatoes well and return them to the pot. Using a potato masher or ricer, begin mashing potatoes to your preferred texture. Stir in half the warm butter and cream mixture with 1 teaspoon salt. Optionally, use a hand mixer on low speed for 1-2 minutes to break up larger chunks, being careful not to overmix.
- Finish Mashed Potatoes: Add the remaining butter and cream mixture and stir well. Mix in the grated Gruyere cheese slowly to allow it to melt evenly. Stir in half of the caramelized onions and season with additional salt and freshly ground black pepper to taste. Mix gently and taste frequently to achieve the desired seasoning.
- Serve: Spoon mashed potatoes into a serving dish and top with the remaining caramelized onions. For different serving sizes: cut recipe in half for 4 servings, or double for 12 to 16 servings, adjusting salt carefully and tasting as you season.
Notes
- For advance prep, soak peeled and chopped potatoes in cold water in the refrigerator for up to 18 hours to prevent browning.
- Use a potato masher or ricer for the best texture; avoid overmixing to prevent gummy potatoes.
- Taste frequently while seasoning with salt to balance flavors perfectly.
- Gruyere cheese adds a nutty richness; substitute with another melting cheese if desired.
- This recipe scales well—double or halve the quantities as needed.
Nutrition
- Serving Size: 1 cup
- Calories: 320
- Sugar: 4g
- Sodium: 320mg
- Fat: 22g
- Saturated Fat: 14g
- Unsaturated Fat: 7g
- Trans Fat: 0.3g
- Carbohydrates: 26g
- Fiber: 2g
- Protein: 7g
- Cholesterol: 70mg
