Au Gratin Potatoes (Restaurant Copycat)

⏱️ 90 minutes👥 8 servings❤️ Taste: 10/10
Au Gratin Potatoes (Restaurant Copycat)

Nutrition Facts

Calories
385
Protein
14g
Carbs
38g
Fiber
3g

Health Benefits

Gut Health4/10
Anti-Inflammatory5/10
Blood Sugar Control4/10

Ingredients

  • •- 3 lbs russet potatoes, peeled and sliced into ⅛-inch rounds
  • •- 4 tablespoons unsalted butter
  • •- 3 tablespoons all-purpose flour
  • •- 2½ cups whole milk, warmed
  • •- 1½ cups sharp cheddar cheese, freshly shredded
  • •- 1 cup Gruyère cheese, freshly shredded
  • •- ½ medium yellow onion, finely minced
  • •- 3 cloves garlic, minced
  • •- 1¼ teaspoons kosher salt
  • •- ½ teaspoon freshly ground black pepper
  • •- ¼ teaspoon ground nutmeg

Instructions

  1. 1Preheat your oven to 375°F and butter a 9x13-inch baking dish generously.
  2. 2Slice potatoes uniformly using a mandoline slicer or sharp knife to ensure consistent ⅛-inch thickness for even cooking. Place sliced potatoes in a large pot of cold salted water.
  3. 3Bring potatoes to a boil over high heat, then reduce to medium and parboil for 8 minutes until slightly tender but still firm. Drain thoroughly and set aside.
  4. 4Heat milk in a separate saucepan over medium-low heat until warm to the touch, about 3-4 minutes. Keep warm but do not boil.
  5. 5Melt butter in a large saucepan over medium heat until foaming, about 2 minutes. Add minced onion and cook until softened and translucent, about 4 minutes. Stir in garlic and cook until fragrant, about 1 minute more.
  6. 6Sprinkle flour over the butter mixture and whisk constantly for 2 minutes until golden and nutty-smelling to create a proper roux. This removes the raw flour taste.
  7. 7Gradually pour warm milk into the roux while whisking continuously to prevent lumps, adding about ½ cup at a time. Continue whisking until sauce thickens and coats the back of a spoon, about 5-6 minutes.
  8. 8Remove from heat and stir in 1 cup cheddar cheese and ½ cup Gruyère until completely melted and smooth. Season with salt, black pepper, and nutmeg, adjusting to taste.
  9. 9Layer one-third of the parboiled potato slices in the prepared baking dish, overlapping slightly. Pour one-third of the cheese sauce over potatoes, spreading evenly. Repeat layering twice more with remaining potatoes and sauce.
  10. 10Combine remaining ½ cup cheddar and ½ cup Gruyère, then sprinkle evenly over the top layer.
  11. 11Cover dish tightly with aluminum foil and bake for 35 minutes until potatoes are fork-tender and sauce is bubbling around the edges.
  12. 12Remove foil and continue baking uncovered for 20-25 minutes until top is golden brown and beautifully crusted.
  13. 13Let dish rest for 15 minutes before serving to allow sauce to set and make portioning easier. The potatoes will firm up slightly and slice cleanly.