Kill the crab before cleaning if it is still alive. Dunk the crab in boiling water for 60 seconds. Remove and submerge it in cold water.
Pull the shell off, pull from the back of the crab first. Keep the white meat only and discard the rest.
Cut into quarters by splitting down the middle from head to tail. Remove the meat from the legs and claws. Blanch the big leaves of the cabbage so they are cooked but still crispy.
Mix mayonnaise with lemon juice, salt and pepper then stir it in the crab. Finishing up by spreading out on the cabbage leaf. Put a spoon full of the crab in the center and fold it like a burrito to enjoy.