Place the duck skins on a board and, using a sharp knife, remove most of the fat. Reserve the skins.
Using a small saucepan, render the duck fat with the star anise, cinnamon stick and sansho pepper over low heat for about 15 minutes.
Pass the fat through a fine filter and reserve only the liquid fat.
Line two heavy-based baking trays with non-stick baking paper. Spread