In a small bowl, beat the egg whites with a fork until frothy. Then beat in the 2 tablespoons of milk.
Have corn, egg white mixture, chicken stock, salt cornstarch mixture and chopped ham within easy reach.
In a 2-quart saucepan, bring the chicken stock to a boil over high heat. Add the corn and salt, and, stirring constantly, bring to a boil again. Give the cornstarch mixture another quick stir to recombine it and pour it into the soup. Cook, stirring constantly, until the soup has thickened and become clear.
Turn off the heat and immediately add ham and pour in the egg white mixture, stirring only once. Serve immediately with green onion garnish.
Recipe by Culinary Mamas at https://culinarymamas.com/chinese-velvet-corn-soup/