Ingredients:

  • 250g (2 cups) all-purpose flour, plus more for dusting
  • 125g (1/2 cup + 2 tablespoons) unsalted butter, chilled and cubed
  • 60g (1/4 cup) vegetable shortening, chilled
  • 1/2 teaspoon salt
  • 120ml (1/2 cup) ice water
  • 700g (approximately 1.5 lbs) Yukon Gold potatoes, peeled and thinly sliced (about 1/8 inch thick)
  • 2 tablespoons unsalted butter
  • 1 medium yellow onion, finely chopped
  • 2 cloves garlic, minced
  • 300ml (1 1/4 cups) heavy cream
  • 120ml (1/2 cup) milk
  • 1/4 teaspoon ground nutmeg
  • Salt and freshly ground black pepper to taste
  • 1/4 cup grated Gruyere cheese (optional)
  • 1 large egg, beaten (for egg wash)

Instructions:

  1. Combine flour, butter, shortening, and salt in a food processor or by hand. Gradually add ice water until the dough comes together. Form into a disc, wrap in plastic wrap, and chill for at least 30 minutes.
  2. Melt butter in a large skillet. Sauté onion until softened, then add garlic and cook for another minute.
  3. Add heavy cream, milk, and nutmeg to the skillet. Season with salt and pepper. Bring to a simmer.
  4. Gently stir in the sliced potatoes, ensuring they are mostly submerged in the cream mixture. Cook over low heat, stirring occasionally, until the potatoes are tender but still hold their shape (about 15-20 minutes). Remove from heat. Stir in Gruyere cheese (if using). Let cool slightly.
  5. Preheat oven to 200C / 400F. Roll out the chilled dough into a large rectangle (about 12x18 inches).
  6. Spread the potato mixture evenly over the dough, leaving a small border at one of the long edges.
  7. Starting from the opposite long edge, tightly roll up the dough into a log.
  8. Cut the log into 6 equal slices (rolls). Place the rolls, cut-side up, on a baking sheet lined with parchment paper.
  9. Brush the tops of the rolls with beaten egg. Bake for 35-40 minutes, or until golden brown and the potatoes are heated through.
  10. Let the rolls cool slightly on the baking sheet before serving.