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These Twice Baked French Onion Mashed Potatoes are everything you want in a comforting side dish. Creamy, cheesy, and topped with golden caramelized onions, they take classic mashed potatoes to a whole new level with the rich flavors of French onion soup. Whether you are cooking for a holiday or looking for a cozy dinner addition, this dish will impress with its rustic elegance and deep savory taste.
This recipe quickly became a favorite in my house after the first time I made it. The caramelized onions add such a rich depth that everyone asks for seconds.
Ingredients
- Russet potatoes: a fluffy and light mashed potato base choose firm, unblemished potatoes for best texture
- Yellow onions: slowly caramelized to develop sweetness and that signature French onion flavor
- Butter: to add richness and silkiness to the mash and onion topping
- Heavy cream: makes the mashed potatoes velvety and smooth whole milk cream is best
- Gruyère cheese: that melts beautifully and brings an authentic French onion soup taste
- Salt and freshly ground black pepper: to perfectly season every layer
- Olive oil: helps caramelize onions evenly without burning use extra virgin for the best flavor
- Fresh parsley: as an optional garnish adds a bright touch and fresh aroma
Step-by-Step Instructions
- Caramelize the Onions:
- Slice your yellow onions thin. Heat olive oil and butter in a pan over medium-low heat. Add the onions and cook slowly for about 30 to 40 minutes, stirring frequently. Watch for them to turn deep golden brown and jam-like. This slow cooking brings out their natural sweetness and creates that rich French onion aroma.
- Boil and Mash the Potatoes:
- Peel the russet potatoes and chop into evenly sized chunks. Place in a large pot of salted water and bring to a boil. Cook until potatoes are fork-tender, about 15 to 20 minutes. Drain well then mash while still hot. Add in butter, warm heavy cream, salt, pepper, and shredded Gruyère. Stir until smooth, creamy, and cheesy.
- Assemble and Bake:
- Butter a baking dish generously. Spread your cheesy mashed potatoes evenly inside. Spoon the caramelized onions on top and sprinkle some additional Gruyère if you like. Bake at 375 degrees Fahrenheit until the top turns golden and bubbling, about 25 minutes.
- Garnish and Serve:
- Once out of the oven, sprinkle with chopped fresh parsley for a pop of color and freshness. The onions should be golden with slightly crisp edges. Serve warm and enjoy the creamy plus crispy textures together.
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The caramelized onions are definitely my favorite part of this dish. It reminds me of cozy family dinners where everyone gathers around the table, and the smell of these onions cooking always fills the kitchen with warmth.
Storage Tips
Store leftovers in an airtight container in the refrigerator for up to 3 days. To keep the creamy texture when reheating, bake covered with foil in a preheated oven until warmed through. Microwaving works for quick servings but may lessen the crisp onion topping.
Ingredient Substitutions
If you want a slightly creamier mash, Yukon Gold potatoes work well though the texture changes a bit. For the cheese, a sharp white cheddar can be used but Gruyère gives the best classic French onion flavor. Replace heavy cream with half and half for a lighter option, though the dish will be less rich.
Serving Suggestions
These potatoes pair beautifully with herb-crusted roast beef, garlic butter roast chicken, or crispy fried chicken for a full comfort food feast. For a smoky contrast, oven-roasted smoked sausage adds a robust flavor complement. If you want to go all-in on potatoes, try pairing with cheesy scalloped potatoes for a satisfying combo.
Common Recipe Questions
- → What potatoes work best for this dish?
Russet potatoes are ideal due to their starchy texture, which yields a fluffy mash that soaks up butter and cream nicely. Yukon Golds offer a creamier option, while waxy potatoes like reds are less suited.
- → How do I caramelize the onions properly?
Cook thinly sliced yellow onions slowly in butter and olive oil over medium-low heat, stirring often for 30-40 minutes until they turn deep golden brown and jammy.
- → Can I prepare this dish ahead of time?
Yes, assemble it and refrigerate before baking. When ready, bake until the top is bubbly and golden. Leftovers keep well refrigerated for up to 3 days.
- → What cheese complements these potatoes best?
Gruyère cheese melts smoothly and adds a nutty, savory depth that pairs perfectly with the caramelized onions and creamy potatoes.
- → How do I reheat leftovers without losing texture?
Reheat covered in foil in the oven to maintain moisture and crisp topping, or microwave in individual portions if short on time.