Beat soft butter, sugar and yolk then add saffron, salt and rhum.
Mix well and add sifted flour, knead briefly and wrap in cling film, let it rest in fridge for about 2 hours.
Roll the dough on a slightly floured surface and print shapes with a cookie cutter.Do not knead together leftover, just stack them one over another and roll again the dough until you finish it. Put cookies on a baking tray and let them rest in fridge for 30 minutes then bake at 356°F/ 180°C for 10-12 minutes.
Store in a tin box for 4-5 days.