The recipe yield is:
Wash corn in stock. Drain corn, reserving stock; chop finely and return to stock. In a cup, mix cornstarch and cold stock to make paste. In heavy 2-quart saucepan, heat oil until hot. Saute green onions & ginger for about 30 seconds, stirring constantly to avoid burning. Add stock & corn; stir & bring to just under boil. Add salt, pepper & sugar. Simmer 15 minutes or until ready to serve. Just before serving, turn up heat again to a bubbly boil. Dribble in cornstarch paste until soup acquires a waxy translucence. It should still be thin, but not watery. Add sherry. Now beat egg white with a fork to a light froth. Turn off heat. Quickly swirl in egg whites. Pour into serving bowl. Garnish with ham. Serve.