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Crispy Potato Roast

Prep Time 25 minutes
Cook Time 2 hours
Total Time 2 hours 25 minutes
Author www.smittenkitchen.com


  • 3 tablespoons salted or unsalted butter , melted
  • 3 tablespoons extra-virgin olive oil
  • Coarse salt
  • 1/2 to 1 teaspoon red-pepper flakes
  • 4 pounds russet potatoes , peeled
  • 1 large onion
  • 8 sprigs thyme
  • Garnishes (optional): Bits of goat cheese, crumbles of bacon and/or
  • bits of crisped pancetta


  1. Preheat oven to 375°F. In a small bowl, combine butter and oil. With a sharp knife or mandoline, slice potatoes crosswise very thinly.
  2. In a large baking dish, pour a tablespoon or so of the butter/oil mixture in the bottom and spread it evenly.
  3. Sprinkle the oil mixture with a few pinches of coarse salt and red pepper flakes, if using; this will allow you to season both the top and underside of the potatoes.
  4. Arrange your potato slices vertically in the dish.
  5. Thinly slice onion and slide slivers between potato wedges, distributing them as evenly as possible.
  6. Brush with remaining oil/butter mixture.
  7. Generously season your dish with salt.
  8. Bake 1 1/4 hours, then arrange thyme sprigs on top and bake until potatoes are cooked through with a crisped top, about 35 minutes more.
  9. If casserole seems to brown too fast, cover it with foil to slow it down.
  10. Add any garnishes, if using, and serve immediately.