Ingredients

For about thirty Guérande shortbread cookies:
  • 400 g flour
  • 380 g salted butter (softened)
  • 170 g unsalted butter (softened)
  • 1 yolk from a hard-boiled egg, crushed
  • 80 g cornstarch or potato starch
  • 45 g caster sugar
  • 3 g Guérande sea salt