Wash the chicken and place in a saucepan. Place 2-3 spoons in the abdominal cavity (as a heat conductor). Add ginger, onion and salt. Cover with cold water. Bring to the boil in an open saucepan. 30 sec. cook, remove from the plate, put the lid on and let cool.
Place the drained chicken in a resealable container, cover completely with dry sherry (fino), close the container. Put in the fridge for 7 days. Remove the chicken and cut thinly.