Twice Baked French Onion Mashed Potatoes

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Golden, cheesy, and irresistibly savory — Twice Baked French Onion Mashed Potatoes are here to elevate your side dish game. This recipe takes the classic comfort of mashed potatoes and layers it with the deep, caramelized flavor of French onion soup. Each bite is a rich combination of creamy potatoes, sweet onions, melty cheese, and subtle herbs, all baked to golden perfection.

Perfect for holidays, cozy Sunday dinners, or anytime you want to impress with something a little extra, this dish brings both elegance and indulgence to your table. It’s not just another mashed potato recipe — it’s a show-stopping side that can easily steal the spotlight from the main course.

Why You’ll Love This Twice Baked French Onion Mashed Potatoes Recipe

This dish is a blend of comfort and sophistication. The smooth, buttery mashed potatoes get a gourmet twist from the slow-cooked caramelized onions and a generous topping of gooey cheese. Baking it a second time adds an irresistible crispy top layer while locking in all the rich, savory flavors inside.

It’s a crowd-pleaser for all ages, easily prepped ahead of time, and versatile enough to pair with everything from roast chicken to holiday ham. Plus, it tastes just as good (if not better) the next day!

What Kind of Onions Should I Use for French Onion Mashed Potatoes?

Yellow onions are the go-to choice for that classic French onion flavor. They caramelize beautifully, turning sweet and jammy with deep golden edges after a slow cook. If you prefer a more delicate taste, sweet onions work too, though they’ll cook faster and may result in a milder flavor. Red onions could be used in a pinch but will give the dish a slightly different taste and color.

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Ingredients for the Twice Baked French Onion Mashed Potatoes

To make this incredibly flavorful side dish, you’ll only need a few staple ingredients, each playing a crucial role in building deep, layered flavor:

• Yukon Gold Potatoes: These have a naturally buttery texture and flavor, making them perfect for creamy mashed potatoes.
• Yellow Onions: Slowly caramelized, they bring that signature French onion depth and sweetness.
• Butter: Essential for richness and smooth texture in the mash.
• Heavy Cream: Adds luxurious creaminess and a slight tang to balance the savory notes.
• Gruyère Cheese: The ultimate melting cheese, its nutty and slightly salty flavor is perfect with caramelized onions.
• Fresh Thyme: Brings an earthy, herby touch that cuts through the richness.
• Salt & Pepper: Fundamental for enhancing all the flavors.
• Chives: Sprinkled on top for a fresh, mild onion kick and visual appeal.

How To Make the Twice Baked French Onion Mashed Potatoes

Step 1: Prep and Boil the Potatoes

Peel and cut the Yukon Gold potatoes into chunks. Boil in salted water until fork-tender, about 15–20 minutes. Drain and set aside.

Step 2: Caramelize the Onions

While the potatoes boil, slice the onions and cook them slowly in butter over medium-low heat. Stir occasionally until they’re golden brown and jammy, about 30–40 minutes. Add a few sprigs of thyme during the last 10 minutes.

Step 3: Mash the Potatoes

Mash the drained potatoes with butter and heavy cream until smooth and fluffy. Season with salt and pepper to taste.

Step 4: Combine with Caramelized Onions

Fold in half of the caramelized onions and half the grated Gruyère cheese into the mashed potatoes. Mix until well incorporated.

Step 5: Bake for the First Time

Transfer the mixture to a greased baking dish. Top with the remaining onions and cheese. Bake at 375°F (190°C) for 20 minutes or until the top is golden and bubbly.

Step 6: Add a Finishing Touch

Sprinkle chopped chives over the baked dish just before serving for added flavor and freshness.

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Serving and Storing Twice Baked French Onion Mashed Potatoes

This indulgent side dish is hearty enough to feed 6 to 8 people as a side, making it perfect for family dinners or festive gatherings. Serve it straight from the oven for the best cheesy, melty texture and rich, onion-forward flavor.

Leftovers? They’re just as delicious the next day. Store any remaining potatoes in an airtight container in the fridge for up to 4 days. To reheat, pop them in a 350°F oven until warmed through or microwave individual portions with a splash of cream to bring back that creamy texture.

What to Serve With Twice Baked French Onion Mashed Potatoes?

Roast Chicken

Classic roast chicken is the perfect match for these creamy, savory potatoes. The juicy meat balances out the richness.

Grilled Steak

A grilled ribeye or sirloin complements the deep onion flavor and makes for an ultra-satisfying dinner.

Holiday Ham

Sweet and salty ham pairs beautifully with the cheesy mash, especially for holiday meals.

Braised Short Ribs

Rich, tender beef short ribs enhance the umami of the dish and create a decadent comfort food pairing.

Green Beans Almondine

A crisp vegetable side brings freshness and crunch to round out the meal.

Caesar Salad

The tangy dressing and crisp romaine help balance out the creamy potatoes nicely.

Garlic Butter Mushrooms

Earthy, buttery mushrooms add a savory depth that mirrors the caramelized onions.

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Frequently Asked Questions

Can I use a different type of cheese?
Absolutely! While Gruyère offers the most authentic flavor, Swiss, mozzarella, or even sharp white cheddar are great alternatives depending on your taste preferences.

Can I make this dish ahead of time?
Yes, you can prepare the mashed potato mixture and assemble the dish a day in advance. Cover and refrigerate, then bake just before serving.

How do I get perfectly caramelized onions?
Low and slow is key. Use medium-low heat, a good amount of butter, and stir often. Don’t rush the process — it takes 30 to 40 minutes to get them truly jammy and golden.

Is this recipe gluten-free?
Yes! This recipe contains no flour or gluten ingredients, making it a naturally gluten-free side dish.

Can I freeze leftovers?
Mashed potatoes can be frozen, but the texture might slightly change upon reheating. For best results, store in a freezer-safe container and reheat in the oven with a bit of added cream.

Save This Pin For Later

📌 Save this recipe to your Pinterest dinner board so you can come back to it any time.
And let me know in the comments how yours turned out. Did you switch up the cheese? Try adding bacon? Maybe a splash of wine in the onions?

I love hearing how others make these recipes their own. Questions are welcome too — let’s help each other cook smarter.

Looking for more delicious dinner sides? Check out my daily updates over on Pinterest @LifeWithLivia

Conclusion

Twice Baked French Onion Mashed Potatoes are the kind of dish that turns any meal into something memorable. With their creamy texture, golden baked top, and rich oniony goodness, they bring warmth and elegance to the table.

Whether you’re cooking for a celebration or just craving something indulgent, this recipe delivers comfort and depth in every bite. Save it, share it, and most of all — enjoy it.

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