Stand the corn on its end and run a sharp knife down the sides to remove the kernels. Set the kernels aside and reserve the cobs.
Bring the stock and water to a simmer in a large pot and add the cobs, ginger slices, salt, soy sauce and wine. Simmer the stock, covered, for 45 minutes, then discard the corn cobs and ginger slices.
Add the reserved kernels and simmer for a further 5 minutes. Taste the soup and adjust the seasoning, if necessary. Whisk in the cornstarch mixture while simmering the soup until it thickens to a silky consistency.
Continue simmering the soup and add the beaten eggs in a thin stream, whisking slowly but constantly. The eggs should form thin, wispy threads as they cook. Remove from the heat and stir in the chicken.