Ingredients:

  • 1 1/2 cups All-Purpose Flour
  • 6 Tbsp cold, cubed Unsalted Butter
  • 1/2 cup grated Mature Cheddar Cheese
  • 1 Large Egg Yolk (for dough)
  • 3-5 Tbsp Ice Water
  • 1/2 tsp Salt
  • 8 oz Smoked Bacon (lardons or rashers)
  • 2 large Leeks, white and light green parts, sliced
  • 2 Tbsp Unsalted Butter (for sautéing)
  • 2 cloves minced Garlic
  • 1/2 cup Chicken or Vegetable Stock
  • 1/2 cup Crème Fraîche or Heavy Cream
  • 1 tsp Fresh Thyme Leaves
  • Salt and Black Pepper to taste
  • 3 lbs Starchy Potatoes (e.g., Russet), peeled and chunked
  • 1/2 cup softened Unsalted Butter (for mash)
  • 1/2 cup warm Full-Fat Milk or Cream
  • Pinch freshly grated Nutmeg
  • 1 Large Egg Yolk (for glaze)
  • Salt and White Pepper to taste

Instructions:

  1. For the Pastry: Pulse flour, salt, and grated Cheddar. Cut in the cold butter until coarse crumbs form. Mix in the egg yolk.
  2. Drizzle in ice water gradually until the dough just comes together. Form into a disc, wrap, and chill for at least 30 minutes.
  3. Roll the dough out and line a 9-inch pie plate. Trim edges and prick the base lightly with a fork.
  4. Blind Bake: Line with parchment paper and baking weights. Bake at 375°F (190°C) for 15 minutes. Remove weights and bake for another 5–7 minutes until lightly set. Set aside.
  5. For the Mash: Place peeled potatoes in salted cold water, bring to a boil, and simmer until fork-tender (15–20 minutes). Drain completely.
  6. Return potatoes to the hot pan over low heat for 1–2 minutes, shaking constantly, to evaporate excess moisture (crucial for a dry mash).
  7. Pass the hot, dry potatoes through a ricer or mash thoroughly. Gently fold in the softened butter and warm milk/cream until smooth. Season heavily with salt, white pepper, and nutmeg. Reserve.
  8. For the Filling: Cook the bacon lardons in a frying pan until crisp. Remove bacon and set aside, reserving 1 Tbsp of rendered fat.
  9. Add the butter and sliced leeks to the pan. Sauté gently until soft and translucent (8–10 minutes). Add the garlic during the last minute.
  10. Pour in the stock and simmer, reducing the liquid slightly. Stir in the crème fraîche and fresh thyme. Add the reserved crispy bacon. Taste and adjust seasoning.
  11. Assembly: Spoon the bacon and leek filling evenly into the blind-baked pastry shell. Top with the mashed potato, ensuring the edges are sealed.
  12. Glaze the top of the mash by brushing it lightly with the remaining egg yolk (whisked lightly).
  13. Bake: Bake in a 375°F (190°C) oven for 20–25 minutes, or until the topping is deep golden brown and the filling is visibly bubbling.
  14. Rest the Mashed Potato Pie for 10 minutes before slicing and serving.