You will need 25 small pastry boats.

Sift the flour with the salt and rub in butter. Add the egg yolks and water and work together to form a soft dough. Add more water if necessary, but the dough should not be sticky. Roll into a ball and wrap in clingfilm. Chill in the fridge for at least 30 minutes until firm.

The dough can be stored in the fridge for up to 3 days. Roll out the pastry to just under 1/4inch / 5mm and stamp out boat shapes with the tins. Line the tins with the pastry and stack them one on top of another up to five tins high. Leave the top tin empty. Press the stacks of tlns gently down and leave to chill. Meanwhile, preheat the oven to 200 °C/400°F/Gas 6. To cook, place the stacks of pastry-lined tins on a baking sheet and bake in the oven for about 15 minutes, until the pastry is golden brown. Remove and allow to cool.

These boats can be stored in an airtight container for up to a week before using.