PMix flour and softened butter until dough is homogenous. Roll into a ball and leave it to rest for around 30 minutes.

Preheat the oven fo gas mark 4/170°C (150°C fan).

Roll dough to be about 1/2cm thick. Cut out an even number of 5cm diameter circles.

Put in the oven for about 20 minutes. The biscuit should be slightly crumbly but not too crumbly.

Let them cool then stick them together in pairs with jam.

Lightly beat the egg white, gradually adding icing sugar. Mix in food colouring.

Glaze napolitaine using a teaspoon, and leave half a day to dry before serving.