French Onion Soup Potatoes (Printable)

Roasted potato slices topped with caramelized onions and melted Gruyère cheese. French-inspired comfort in every bite.

# What You Need:

→ Potatoes

01 - 3.3 lbs Yukon Gold or russet potatoes, scrubbed and sliced 1/3 inch thick
02 - 2 tablespoons olive oil
03 - 1/2 teaspoon kosher salt
04 - 1/4 teaspoon freshly ground black pepper

→ Caramelized Onions

05 - 3 large yellow onions, thinly sliced
06 - 2 tablespoons unsalted butter
07 - 1 tablespoon olive oil
08 - 1/2 teaspoon kosher salt
09 - 1 teaspoon fresh thyme leaves or 1/2 teaspoon dried thyme
10 - 1 teaspoon balsamic vinegar

→ Topping

11 - 7 ounces Gruyère cheese, grated
12 - 1 ounce Parmesan cheese, grated (optional)
13 - 2 tablespoons chopped fresh parsley for garnish

# How-To Steps:

01 - Preheat oven to 425°F. Line a large baking sheet with parchment paper. Toss potato slices with olive oil, salt, and pepper. Arrange in a single layer on the prepared sheet.
02 - Roast for 25 to 30 minutes, flipping once halfway through, until golden and tender.
03 - While potatoes roast, heat butter and 1 tablespoon oil in a large skillet over medium-low heat. Add onions and salt; cook, stirring often, for 25 to 30 minutes until deeply golden and caramelized. Stir in thyme and balsamic vinegar; cook 1 to 2 minutes more. Remove from heat.
04 - Reduce oven temperature to 400°F.
05 - Arrange roasted potato slices in a lightly greased baking dish, slightly overlapping. Spoon caramelized onions evenly over the potatoes. Sprinkle Gruyère and Parmesan cheese (if using) over the top.
06 - Bake for 10 to 15 minutes until cheese is melted and bubbling.
07 - Let cool slightly. Garnish with chopped parsley and serve warm.

# Expert Advice:

01 -
  • It borrows the soul of French onion soup without any of the fussy broth work or oven-safe bowls.
  • The potatoes get crispy on the edges while staying creamy inside, creating texture you cannot stop eating.
  • Caramelized onions and melted Gruyère turn humble potatoes into something that feels like a dinner party without the stress.
  • It holds beautifully on a buffet and reheats better than almost any cheesy potato dish I have tried.
02 -
  • Do not try to rush the onions; low and slow is the only way to coax out that deep, sweet flavor without bitterness.
  • If your potato slices are uneven, the thin ones will crisp too much and the thick ones will stay raw, so aim for uniform thickness.
  • Let the dish rest for five minutes after baking or the cheese will slide right off when you serve it.
03 -
  • Use a mandoline to slice the potatoes evenly, but watch your fingers; I have the scars to prove it.
  • If the top is browning too fast, tent the dish loosely with foil and let the cheese finish melting gently.
  • Make a double batch of caramelized onions and freeze half; they are gold for sandwiches, pizzas, and future potato dishes.
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