Quiche Lorraine

• 50 g Gruyère cheese, cut in pieces (opcional)

Pastry

• 75 g butter, unsalted, chilled, cut in pieces, plus extra for greasing
• 150 g flour, plus extra for dusting
• ½ tsp salt
• 50 g water

Filling

• 200 g bacon cubes
• 4 eggs
• 50 g milk
• 100 g crème fraîche
  o bien 100 g cream
• ¼ tsp salt
• 2 pinches ground black pepper