If you're going to serve cold dressed crab you'll need a crab per person. Once you've cooked the crab, your task is to patiently extract all the flesh you can.
To prepare the crab, begin with the legs and claws: crack them and remove the flesh.
Then turn to the body. Turn it over and twist off the tail flap. Push a knife into the line between the main part of the shell and the part to which the legs were attached; twist the knife to open the shell and remove the brown meat.
Keep the main part of the shell as unharmed as you can as you need it to refill with meat to serve.
Finally, and this is the part most requiring patience, go back to the upper body section, snap off the mouth and remove the "dead men's fingers" (the gills). Then scrape as much remaining flesh as you can out of the cavities of the shell.
To dress the crab, neaten the shell "bowl" up if necessary and mix the brown meat with a dash of lemon juice and some fine white breadcrumbs. Season with salt and pepper.
Arrange the brown meat down the centre of the shell and put the white meat on either side.
Decorate with chopped hard-boiled egg, parsley, lemon wedges and lettuce leaves.
Serve with mayonnaise.