The cooking liquid can vary from water or the classic court bouillon to a spicy broth. Before you start, put the live crab in the freezer for 1 hour to desensitize it. The crab will then be easy to handle.
If not already done by the fishmonger, tie the crab with string to keep its claws still. Fill a pan with enough court bouillon to cover the crab. Bring to the boil.
Add the crab and cover the pan; bring back to the boil and cook until the shell of the crab turns red, about 5 minutes per 450 g.
Remove the cooked crab from the pan with a slotted spoon. Transfer to a colander to drain. Let cool, then remove the cooked meat from the shell.