Ingredients:

  • 12.5 oz all-purpose flour
  • 8 oz cold unsalted butter, cubed
  • 1 tsp fine sea salt
  • 6 tbsp ice-cold water
  • 1 large egg
  • 2 lbs Yukon Gold potatoes, peeled and sliced 1/8 inch thick
  • 2 large yellow onions, thinly sliced
  • 2 tbsp Irish butter
  • 0.5 cup heavy cream
  • 1 tsp fresh thyme leaves
  • 0.5 tsp cracked black pepper
  • 0.5 tsp flaky sea salt

Instructions:

  1. Prepare the pastry by pulsing flour, salt, and cold cubed butter until it resembles shaggy crumbs. Add ice water one tablespoon at a time until dough forms. Wrap and chill for 30 minutes.
  2. Melt Irish butter in a skillet over medium heat. Sauté sliced onions until deeply golden and jammy, approximately 15 minutes. Set aside.
  3. Bring a pot of salted water to a boil. Par-cook sliced potatoes for 5 minutes until just barely fork tender. Drain and pat dry.
  4. Roll out half the pastry and line a 9-inch deep-dish pie plate. Layer potatoes and sautéed onions, seasoning with thyme, pepper, and sea salt between layers.
  5. Pour heavy cream over the filling. Roll out the remaining pastry and place over the top, crimping the edges to seal.
  6. Cut steam vents in the top crust and brush with beaten egg wash. Bake at 400°F (200°C) for 35 minutes until the crust is mahogany-colored and golden-brown.