Heat the oil in a saucepan over medium-high heat. Add the corn, and fry for about 30 seconds. Pour in the fish stock, and season with salt and pepper. Simmer over medium-low heat for a few minutes. Drizzle in the egg while slowly stirring the soup to create a white swirl.
To serve, divide the crabmeat into 4 bowls, and ladle the hot soup over it.