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French Onion Scalloped Potatoes
I love a holiday main dish, but I’m really there for the sides. Give me the potatoes, the stuffing, and anything with a golden, cheesy top, and I’m happy. These French Onion Scalloped Potatoes are exactly the kind of dish I want on my holiday table.
Thinly sliced Yukon Gold potatoes get layered with sweet caramelized onions, cream, and Gruyère, so you get those cozy French onion soup flavors in every bite. That’s what I love about holiday sides: taking something familiar, like scalloped potatoes, and making it feel a little extra special for the people you’re feeding.
These are perfect for Thanksgiving or Christmas dinner, and you can make the onions ahead to save yourself some time. They take a little patience, but most of the baking is hands-off, leaving you free to work on the rest of dinner. Just give them a few minutes to rest before everyone starts sneaking bites!
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Equipment
- 1 Large skillet
- Mandolin slicer optional
Ingredients
For the caramelized onions
- 3 tablespoons butter
- 1 tablespoon olive oil
- 3 large yellow onions thinly sliced
- 1 teaspoon kosher salt
- ½ teaspoon black pepper
- 1 teaspoon sugar
- 1 teaspoon garlic powder
- 1 teaspoon dried thyme
- ½ cup beef broth
For the potatoes
- 2 1/2 pounds Yukon Gold potatoes sliced into even ⅛-inch-thick rounds
- 1½ cups heavy cream
- 1 teaspoon kosher salt
- ¼ teaspoon black pepper
- 1 teaspoon fresh thyme leaves
- 1½ cups freshly shredded Gruyère cheese divided
- Fresh thyme for serving optional
Instructions
- Caramelize the onions. Heat the butter and olive oil in a large skillet over medium-low heat. Add the onions, salt, pepper, sugar, garlic powder and thyme and mix. Cook for 40–50 minutes, stirring occasionally, until deeply golden and soft. If the pan starts to dry out or the onions stick, add a splash of water.
- Add the flavor. Pour in the beef broth, scraping up any browned bits. Simmer for 3–5 minutes, until most of the liquid has cooked off and the onions are jammy.
- Prep the potatoes. Preheat the oven to 375°F. Grease a 9×13-inch baking dish with nonstick cooking spray. In a large bowl, toss the sliced potatoes with the heavy cream, salt, pepper, and fresh thyme.
- Layer the casserole. Arrange half the potatoes in overlapping layers in the baking dish. Spread half the onions over them and sprinkle with half the Gruyère. Repeat with the remaining potatoes, onions, and cheese. Pour any cream left in the bowl evenly over the top.
- Bake covered. Cover tightly with foil and bake for 50–60 minutes, until the potatoes are nearly tender when pierced with a knife. If they’re still firm, cover and continue baking before moving to the next step.
- Brown the top. Remove the foil and bake for another 15–20 minutes, until the potatoes are fully tender and the top is golden and bubbly. For extra browning, broil for 1–2 minutes, watching closely.
- Rest and serve. Let rest for 10–15 minutes so the cream can thicken slightly. Garnish with fresh thyme, if using, and serve warm.
Nutrition
If you make this recipe, I’d love to see it! Tag me on Instagram @thecookingmawma and let me know what you think.
It’s absolutely delicious and I hope you love it as much as our family!
Tips for Making This Recipe
- Keep the potato slices even. Aim for ⅛-inch-thick slices so they cook evenly. A mandoline makes this easier, but a sharp knife works, too.
- Make the onions ahead. Caramelize the onions up to 3 days in advance and refrigerate in an airtight container. This saves a big chunk of prep time when you’re ready to assemble!
- Check before uncovering. Pierce the potatoes in the center with a knife. They should be nearly tender before you remove the foil; if they’re still firm, keep baking covered so the cheese doesn’t brown too soon.
Frequently Asked Questions
Can I use a different cheese instead of Gruyère?
Do I need to peel the Yukon Gold potatoes?
Why are my scalloped potatoes still firm?
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