French Onion Soup Potatoes (Print Version)

Golden roasted potatoes with caramelized onions and melted Gruyère, inspired by French onion soup flavors.

# Ingredient List:

→ Potatoes

01 - 3.3 lbs Yukon Gold or russet potatoes, scrubbed and sliced ⅓ inch thick
02 - 2 tbsp olive oil
03 - ½ tsp kosher salt
04 - ¼ tsp freshly ground black pepper

→ Caramelized Onions

05 - 3 large yellow onions, thinly sliced
06 - 2 tbsp unsalted butter
07 - 1 tbsp olive oil
08 - ½ tsp kosher salt
09 - 1 tsp fresh thyme leaves (or ½ tsp dried thyme)
10 - 1 tsp balsamic vinegar

→ Topping

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

# Steps:

01 - Preheat oven to 425°F. Line a large baking sheet with parchment paper.
02 - Toss potato slices with olive oil, salt, and pepper. Arrange in a single layer on the prepared sheet. Roast for 25–30 minutes, flipping once, until golden and tender.
03 - While potatoes roast, heat butter and 1 tbsp oil in a large skillet over medium-low heat. Add onions and salt; cook, stirring often, for 25–30 minutes until deeply golden and caramelized. Stir in thyme and balsamic vinegar; cook 1–2 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, if using) over the top.
06 - Bake for 10–15 minutes until cheese is melted and bubbling.
07 - Let cool slightly. Garnish with chopped parsley and serve warm.

# Helpful Hints:

01 -
  • It gives you all the deep, savory comfort of French onion soup without the fuss of broth or bread bowls.
  • The potatoes get crispy on the edges and creamy in the middle, soaking up every bit of onion sweetness.
  • You can prep the onions ahead and assemble everything in under ten minutes when you're ready to bake.
  • It works as a hearty side dish or a full vegetarian main when you pair it with something green and crunchy.
02 -
  • Do not rush the onions or crank up the heat, or they'll burn and taste bitter instead of sweet and jammy.
  • Slice your potatoes evenly so they cook at the same rate, otherwise some will be mushy while others stay hard.
  • If your cheese isn't browning enough, switch the oven to broil for the last two minutes, but watch it like a hawk.
03 -
  • Use a mandoline to slice your potatoes quickly and evenly, but watch your fingers because those blades are unforgiving.
  • If your onions start sticking to the pan, add a splash of water or broth and scrape up the browned bits for even more flavor.
  • Grate your own cheese instead of buying pre-shredded, it melts smoother and tastes infinitely better.
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