Ingredients

The following ingredients have 12 Servings
  • 15 medium potatoes (Yukon Gold is best)
  • 2 medium onions
  • 2 tablespoons butter
  • 4 cloves garlic (pressed or finely minced)
  • 3 tablespoons all purpose flour
  • 1 teaspoon salt
  • 1/2 teaspoon pepper
  • 3 tablespoons white wine (optional)
  • 2 cups milk
  • a pinch of nutmeg
  • 1/2 teaspoon smoked paprika
  • 1/2 teaspoon dried thyme
  • 1 1/4 cup shredded cheddar cheese (not aged cheddar, reserve 1/2 cup)
  • 1 cup shredded parmesan cheese (freshly grated is best, reserve 1/4 cup)

Instruction

  • Preheat your oven to 400 degrees Fahrenheit (use 375 degrees if you don't have a convection option on your oven). Grease a large rectangular baking dish with cooking spray or butter and set it aside.
  • Wash and peel the potatoes and slice them about 1/4 inch thick using a mandoline slicer.
  • Peel the onions and slice them on the mandoline slicer to about 1/8 inch thick. Set the potatoes and onions aside in a bowl.
  • Heat a medium pot over medium heat on the stove and add the butter. Add the garlic once the butter is melted and let the garlic heat up in the butter.
  • Sprinkle the flour, salt and pepper over the garlic and butter and whisk everything together, letting the flour toast over the heat while you whisk almost constantly.
  • Slowly drizzle in the white wine (if using) after the flour has toasted for about 3 minutes, whisking constantly.
  • Drizzle in the milk in a slow, steady stream, whisking constantly until a smooth sauce forms.
  • Turn the heat to medium low and continue to cook, whisking regularly, as the sauce thickens.
  • Add a pinch of nutmeg, the paprika and thyme, and whisk until combined.
  • Switch to a wooden spoon or heat-safe spatula and add the cheese by the handful, stirring gently until the cheese has melted. RESERVE 1/2 cup cheddar and 1/4 cup Parmesan for sprinkling over the top of the scalloped potatoes.
  • Start assembling the casserole by layering one third of the potatoes, one third of the onions, and then one third of the sauce in the bottom of the dish. Repeat 2 more times, layering potatoes, onions, then sauce until the dish is full.
  • Smooth out the sauce over the top and push it into any cracks or gaps between the potatoes and onions.
  • Top with the remaining cheese and bake at 400 degrees Fahrenheit for about 1 hour or until the potatoes are fork tender and the cheese on top is browned and bubbly.
  • Let stand for about 5 minutes before serving.