Using the whisk on a hand mixer, beat the butter with the sugar, egg and salt until light and fluffy. Stir in the chestnut puree. Mix in the flour and nuts, combine quickly to form a dough. Shape into approx. 20 balls, place on a baking tray lined with baking paper, flatten a little.
Approx. 20 mins. in the centre of an oven preheated to 200°C. Remove from the oven, allow to cool slightly, then leave to cool completely on a rack.