Ingredients

For about thirty Guérande shortbread cookies:
  • 400 g (14 oz) flour
  • 380 g (13.5 oz) salted butter (softened)
  • 170 g (6 oz) unsalted butter (softened)
  • 1 yolk from a hard-boiled egg, crushed
  • 80 g (2.8 oz) cornstarch or potato starch
  • 45 g (1.6 oz) caster sugar
  • 3 g Guérande sea salt