Measure the soy sauce into a cup.
Add the cornstarch and stir until it dissolves completely (this will be the thickener for the sauce)...set aside.
Pour the chicken stock into a medium sauce pan.
Add the fish sauce, chili, green onion, lime juice, and sugar to the saucepan...bring to a boil.
Reduce heat to medium and add the reserved soy mixture.
Stir occasionally until the sauce thicken, about 2 minutes.
Remove from heat.
Adjust seasonings to taste.
Serve warm with Thai grilled fish or meats, or with fresh dumplings