Heat chicken stock, ginger, garlic powder, and salt/pepper in a large pot on the stove until just boiling.
Turn heat down to low.
In a separate cup or container, mix together about a cup of the hot broth with the cornstarch until smooth. Set aside.
In a measuring cup, beat the eggs.
Stir the hot broth to create a slow swirl. While the broth is swirling, SLOWLY add the eggs.
Add the corn, scallions, and reserved cornstarch/broth mixture. Heat for 2-3 more minutes until thickened.
Before serving, stir in toasted sesame oil.