French Onion Potato Slices (Print Version)

Golden roasted potatoes meet caramelized onions and bubbling Gruyère in a warm side loaded with flavor.

# What You’ll Need:

→ Potatoes

01 - 4 large Yukon Gold potatoes, scrubbed and sliced into ½-inch rounds
02 - 2 tablespoons olive oil
03 - ½ teaspoon kosher salt
04 - ¼ teaspoon black pepper

→ Caramelized Onions

05 - 2 large yellow onions, thinly sliced
06 - 2 tablespoons unsalted butter
07 - 1 tablespoon olive oil
08 - ½ teaspoon sugar
09 - ¼ teaspoon salt
10 - 1 teaspoon fresh thyme leaves or ½ teaspoon dried thyme

→ Topping

11 - 1 cup (100 grams) grated Gruyère cheese
12 - 2 tablespoons fresh parsley, chopped (optional)

# How to Make It:

01 - Preheat oven to 425°F. Line a baking sheet with parchment paper.
02 - Toss potato slices with olive oil, kosher salt, and black pepper in a large bowl. Arrange potatoes in a single layer on the prepared baking sheet and roast for 25 to 30 minutes, flipping halfway through, until golden and tender.
03 - Heat butter and olive oil in a large skillet over medium-low heat. Add sliced onions and salt, cooking while stirring frequently for 10 minutes until softened. Sprinkle sugar and thyme, then continue cooking for an additional 20 to 25 minutes, stirring occasionally until deeply golden and caramelized. Reduce heat if onions brown too quickly.
04 - Remove roasted potatoes from the oven and arrange them slightly overlapping in a shallow baking dish or ovenproof skillet. Spread caramelized onions evenly over the potato slices.
05 - Sprinkle the grated Gruyère cheese evenly over the caramelized onions.
06 - Return the dish to the oven and bake for 10 to 12 minutes until the cheese melts and bubbles. For additional browning, broil for 2 to 3 minutes, monitoring carefully.
07 - Garnish with chopped parsley if desired and serve hot.

# Additional Tips::

01 -
  • It captures every cozy flavor of French onion soup without the broth, giving you something you can actually hold and layer.
  • The caramelized onions take time but reward you with such richness that a little cheese does all the heavy lifting.
  • This works as a side or a vegetarian main, and it tastes just as good reheated the next day.
02 -
  • The onions are the heart of this dish, and they truly need the full 20 to 25 minutes of slow cooking to develop their sweetness and depth, no shortcuts.
  • Don't slice your potatoes too thin or they'll turn to mush before the cheese even melts, and don't slice them too thick or they'll still be hard when everything else is done.
03 -
  • Don't walk away from the onions while they caramelize, even though the process seems to take forever, because the difference between golden and burnt happens faster than you'd think.
  • If you have an ovenproof skillet, caramelize the onions right in it, then layer everything in the same pan to cut down on cleanup and keep all those flavorful browned bits.
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