For the best-tasting Dungeness crab, buy it live and either have your fishmonger steam it and clean it for you or take it home and steam it yourself just before you’re ready to eat. If you’ve purchased your crab cooked, store it on ice in the refrigerator until you’re ready to use it (ideally no more than 8 hours after purchase). If you purchased your crab live, keep it on ice until you are ready to steam it (ideally no more than about 8 hours after purchase).
To steam the crab, bring 1 to 2 inches of water to a boil in a pot that is wide enough and deep enough to accommodate a whole crab. Place the crab in a steamer basket in the pot, cover and steam for 15 to 20 minutes.
Remove the crab from the steamer and let it rest until cool enough to handle. Then grasp the legs in one hand to use as a handle as you pull off the top red shell with your other hand. Working over the sink, rinse the yellow liquid from the body.
Remove the feathery, white-gray lungs at the base of the legs with your fingers.
Remove the mandibles (pincer-looking mouth part) from between the front claws.
Turn the crab over and pull off the triangle-shaped, cream-colored “apron” from the center of the shell, grasping the top of the triangle and pulling down to remove.
Cut the body in half.
To section the legs, use a knife to separate each leg and a part of the body—giving you a leg with a piece of the body attached at one end.
Serve the legs and the body as is or use them in a seafood stew, such as Cioppino.