To shell the crabs, first remove all the legs and the large claws by twisting and pulling them away from the body.

Turn the shell over and, using your thumbs, push the body away from the flat shell. Set the body aside.

Remove the stomach sack and the lungs or dead man's fingers and discard them. Using a small teaspoon, scrape the brown body meat out of the flat shell.

Using a sharp knife, cut the body of the crab in four pieces and using a pick or a skewer, push out all the meat.

Crack the large claws and remove the meat in one piece if possible. Crack the legs and remove the meat as well, leaving the small, thin legs in the shell. Set all the meat aside. Scrub the shells if desired to use for serving.

Heat the oil in a small saute pan or frying pan. Chop the white parts of the spring onions and add to the oil with the green pepper, celery and garlic. Saute over gentle heat for about 10 minutes, stirring often to soften the vegetables but not brown them. Remove from the heat and set aside. When cool, add the mayonnaise, mustard, tabasco, Worcestershire sauce, pimento and finely chopped tops of the spring onions.

Spoon the reserved brown body meat from the crabs back into each shell or serving dish. Mix the remaining crab meat with the dressing, reserving the crab claws for garnish, if desired. They may also be shredded and added to the other crab meat. Do not overmix the sauce as the crab meat should stay in large pieces. Spoon into the shells on top of the brown body meat, sprinkle with chopped parsley and place the crab shells on serving plates, surrounding them with lettuce leaves, if desired. Garnish with the shelled crab claws and use the crab legs if desired. Sprinkle with parsley and serve immediately.