CUT THE CHICKEN BREASTS into fine shreds 8 cm long. Mix them with the egg white, salt and cornstarch. Chill for about 20 minutes. Heat the oil in a wok or large skillet until moderately hot. Add the chicken mixture and stir-fry it quickly in the oil to keep it from sticking. Cook until it turns white, which should take about 1 minute. Drain the chicken immediately in a colander or sieve and drain off the oil. Clean the wok and add about 1 tablespoon of the drained oil. Reheat until it is hot. Add the sesame seeds and stir-fry them for 1 minute or until slightly brown. Add the sauce ingredients and bring to a boil. Return the cooked chicken to the pan and stir-fry the mixture for another 2 minutes, coating the pieces thoroughly with the sauce and sesame seeds. Serve at once, or let cool and serve at room temperature.