Slice the pork into 1/2-cm (1/4-in) thick slices and marinate for 30 minutes.
Put the wu-hsiang and ground rice in a dry saucepan and cook over a low heat until they are golden brown.
Roll the pork slices in the prepared rice powder and arrange in a bowl.
Steam for 1 hour.
Lay the cooked pork on a bed of raw cos lettuce on a warmed plate and serve at once.