How to Make It
In a large pot, melt the butter in the vegetable oil. Add the shallots, season with salt, cover and cook over moderate heat, stirring a few times, until the shallots are softened, 5 minutes. Add the corn kernels and cook for 4 minutes, stirring. Add the ginger and wine and cook over moderately high heat until the wine is almost evaporated, 2 minutes. Add 3 cups of the stock and bring to a boil. Cover and simmer over moderate heat until the corn is tender, about 5 minutes longer.
Transfer the soup to a food processor and process to a slightly chunky puree; return to the pot. Add the ham, season with salt and bring to a bare simmer over low heat.
In a small bowl, beat the eggs with the remaining 2 tablespoons of stock. Gradually add the eggs to the soup, stirring constantly, until the soup is very thick, 30 seconds. Remove from the heat. Ladle the soup into bowls and top with the scallions and crab. Drizzle lightly with chile oil and serve.