Place broth in a large pot and bring to a boil. Add shrimp, ham, water, chestnuts, and corn. Reduce heat to medium and simmer, stirring frequently. Add cornstarch solution and cook, stirring, until soup boils and thickens slightly. Turn off heat. Add egg whites, stirring until they form long threads.
Stir in green onion, sesame oil, pepper and salt, to taste.
Recipe courtesy of Martin Yan