If using frozen crab meat, blanch the flesh in boiling water for 30 seconds. Remove with a
slotted spoon and set aside.
In a large saucepan, bring the water to the boil with the crab and sweetcorn and simmer for 2
minutes. Season with the salt and pepper. Stir in the cornflour, if using, and continue stirring
until the soup has thickened. Rapidly stir in the egg and serve.