Print

French Onion Scalloped Potatoes Recipe

Print Recipe

5 Stars 4 Stars 3 Stars 2 Stars 1 Star

4.6 from 5 reviews

Delicious French Onion Scalloped Potatoes combine caramelized sweet onions and tender russet potatoes baked in a creamy gruyere cheese sauce, topped with seasoned bread crumbs for a crispy finish. This comforting side dish is perfect for family dinners or holiday gatherings.

Ingredients

Units Scale

Onions

  • 4 sweet onions, thinly sliced
  • 4 tablespoons unsalted butter
  • kosher salt and pepper, to taste
  • 1/2 teaspoon dried thyme

Potatoes

  • 3 pounds russet potatoes, peeled and thinly sliced

Sauce

  • 4 tablespoons unsalted butter
  • 4 tablespoons all-purpose flour
  • 3 1/2 cups milk
  • kosher salt and pepper, to taste
  • 1/4 teaspoon freshly grated nutmeg
  • 12 ounces freshly grated gruyere cheese, divided

Topping

  • 1/3 cup seasoned bread crumbs

Instructions

  1. Preheat Oven: Preheat the oven to 375 degrees F to prepare for baking the scalloped potatoes.
  2. Caramelize Onions: Thinly slice the onions. Heat 4 tablespoons of unsalted butter in a skillet over medium heat. Add the onions with a pinch of kosher salt and pepper, stirring occasionally. Cook for 10 minutes until softened, then reduce heat to medium-low, add dried thyme, and cook for 30 to 40 minutes until the onions are golden and caramelized, stirring often. Adjust heat or add water if onions start burning or not cooking properly.
  3. Slice Potatoes: Use a mandoline or sharp knife to slice the peeled russet potatoes very thinly, about ⅛ inch thick or thinner. To prevent browning, place sliced potatoes in a bowl of ice water if slicing ahead of time.
  4. Make the Sauce: In a saucepan, melt 4 tablespoons of butter over medium heat. Whisk in 4 tablespoons of flour to form a roux, cooking for 2 to 3 minutes until golden and fragrant. Slowly whisk in 3 ½ cups of milk, continuing to whisk until smooth. Season with salt, pepper, and grated nutmeg. Reduce heat to low and stir in half of the grated gruyere cheese (6 ounces) until melted. Adjust seasoning if needed.
  5. Assemble Layers: In a baking dish, layer half of the sliced potatoes, then half of the cheese sauce, followed by half of the caramelized onions, and half of the remaining grated gruyere cheese. Repeat the layers with the remaining potatoes, cheese sauce, caramelized onions, and gruyere cheese. Finish by sprinkling the seasoned bread crumbs evenly on top.
  6. Bake: Bake the assembled dish uncovered in the preheated oven for 60 minutes until the potatoes are tender and the top is golden brown. If the topping browns too quickly, tent the dish with foil.
  7. Rest and Serve: Let the scalloped potatoes cool slightly before serving to allow the sauce to thicken and flavors to meld.

Notes

  • If onions start to stick or burn during caramelizing, add a splash of water and reduce heat.
  • Using a mandoline ensures uniform potato slices for even cooking.
  • Potatoes can be sliced and soaked in ice water up to 1 hour in advance to prevent browning.
  • If gruyere cheese is unavailable, a mix of Swiss and mozzarella can be substituted.
  • Seasoned bread crumbs add a crispy topping, but plain bread crumbs or panko can be used if desired.
  • Tenting with foil towards the end of baking prevents over-browning of the top layer.

Find it online: https://yummelle.com/french-onion-scalloped-potatoes-recipe/