Peel the prawns. Place the salt block in the oven at 200ºC. Once hot, take out of the oven and place on a wooden plank or board.
Arrange the dried herbs around the edges, place the prawns on the salt block and set fire to the herbs (the burning herbs will emit smoke that give fragrance to the prawns.)

Turn the prawns over and eat immediately, to prevent them from becoming too salty.