Ingredients:

  • 2 lbs (900g) Yukon Gold potatoes, peeled
  • 1 tbsp (15ml) Olive oil
  • Salt and freshly ground black pepper, to taste
  • 4 tbsp (57g) Unsalted butter
  • 1/4 cup (30g) All-purpose flour
  • 3 cups (710ml) Whole milk
  • 1/2 tsp Ground nutmeg
  • 1/4 tsp Garlic powder
  • 1/2 tsp Paprika
  • 1 cup (100g) Shredded Gruyere cheese (or cheddar), divided
  • Fresh thyme sprigs for garnish (optional)

Instructions:

  1. Preheat oven to 375°F (190°C). Grease a 9x13 inch baking dish.
  2. Thinly slice potatoes using a mandoline or sharp knife (about 1/8 inch thick). Toss with olive oil, salt, and pepper.
  3. In a medium saucepan, melt butter over medium heat. Whisk in flour and cook for 1-2 minutes, stirring constantly to create a smooth roux.
  4. Gradually whisk in milk, making sure to get rid of any lumps. Bring to a simmer, stirring constantly. Reduce heat to low and simmer for 5-7 minutes, until the sauce has thickened slightly. Stir in nutmeg, garlic powder, paprika, salt, and pepper.
  5. Remove from heat and stir in 1/2 cup (50g) of the shredded cheese until melted and smooth.
  6. Layer half of the sliced potatoes in the prepared baking dish, overlapping slightly. Pour half of the cream sauce over the potatoes. Top with the remaining potatoes and remaining cream sauce.
  7. Sprinkle the remaining 1/2 cup (50g) of cheese over the top. Bake for 60-75 minutes, or until the potatoes are tender and the top is golden brown and bubbly. Check for doneness by inserting a fork into the centre of the potatoes; they should be easily pierced.
  8. Let stand for 10-15 minutes before serving. Garnish with fresh thyme sprigs, if desired.