Ingredients:

  • 1 1/4 cups (150g) all-purpose flour, plus more for dusting
  • 1/2 teaspoon (3g) salt
  • 1/2 cup (113g) unsalted butter, very cold and cubed
  • 1/4 cup (60ml) ice water
  • 6 ounces (170g) bacon or pancetta, cut into lardons or small dice
  • 1 small onion or shallot, finely chopped
  • 4 large eggs
  • 1 1/2 cups (360ml) heavy cream
  • 1/4 teaspoon (1.5g) ground nutmeg
  • 1/4 teaspoon (1.5g) salt, plus more to taste
  • 1/4 teaspoon (1.5g) black pepper, plus more to taste
  • 1 cup (100g) grated Gruyère cheese
  • 1 egg yolk
  • 1 tablespoon milk or cream

Instructions:

  1. Combine flour and salt in a food processor or bowl.
  2. Cut in the cold butter until the mixture resembles coarse crumbs.
  3. Gradually add ice water, pulsing or mixing until the dough just comes together.
  4. Form the dough into a disc, wrap in plastic wrap, and chill for at least 1 hour.
  5. Preheat oven to 375°F (190°C).
  6. Roll out the chilled dough on a lightly floured surface to a 12-inch circle.
  7. Carefully transfer the dough to the tart pan and press into the bottom and sides.
  8. Trim any excess dough.
  9. Prick the bottom of the crust with a fork (docking).
  10. Line the crust with parchment paper and fill with baking beans or pie weights.
  11. Bake for 15 minutes.
  12. Remove the parchment paper and baking beans and bake for another 5-10 minutes, or until lightly golden brown.
  13. Cook the bacon or pancetta in a skillet over medium heat until crispy. Remove and set aside, reserving some of the rendered fat.
  14. Sauté the onion or shallot in the reserved bacon fat until softened.
  15. In a large bowl, whisk together the eggs, heavy cream, nutmeg, salt, and pepper.
  16. Sprinkle the cooked bacon or pancetta and sautéed onion or shallot evenly over the pre-baked crust.
  17. Top with the grated Gruyère cheese.
  18. Pour the egg mixture over the cheese.
  19. Brush the crust with egg wash (optional).
  20. Bake for 45-55 minutes, or until the filling is set and lightly golden brown. The center should be just set but still have a slight wobble.
  21. Let cool for at least 15 minutes before slicing and serving.