Preheat the oven to 325°F / 165°C. Line a baking sheet with a silicone mat or parchment paper. Double the baking sheet to provide a layer of insulation.

In a small bowl, using a stiff rubber spatula, mix together the butter and confectioners' sugar until smooth. There should be no lumps of butter or sugar in the honey mixture. Blend in the egg white. Stir in the flour and salt until smooth paste. You can use the stencil to store in the freezer for up to 5 days, or store in an airtight container in the refrigerator if up to 5 days.

Use an offset spatula to spread a thin coat of the honey mixture on the stencil. The thickness of the tuile will depend on the thickness of your stencil. Carefully peel the stencil off the baking sheet. Repeat with as many cookies as you'd like or will fit on the sheet. If you choose to use more than one stencil, you can bake cookies together in multiple batches to keep like-size cookies together. All of the cookies should bake evenly.

Bake in the middle of the oven for about 5 minutes, until they are evenly golden and set. If you want to form the tuile into a shape, allow it to cool for no longer than a minute so that you can safely lift it off the baking sheet, and so that it is still flexible. Use a rubber spatula and drape over a form or twist it into a tube around a pencil. If the cookies harden before you've had a chance to form them, return them to the oven and bake for another minute, then try shaping again.

These cookies can be stored in an airtight container for a couple of days. If it is very humid, they will soften, so take and reshape (see previous step) just before using.