This is from one of my favorite cookbooks: Modern Asian Cooking, the taste of Shanghai
You will need:
2 tsp cornstarch
6 tbsp of soy sauce
1/4 cup of dry sherry
1/2 cup of sugar
2 tbsp of chili sauce or chili garlic sauce
2 packed tbsp of very finely minced peeled ginger or ginger paste from a tube
2 tsp of sesame oil or hot chili sesame oil
First mix 1 tbsp of the soy sauce with the 2 tsp of cornstarch until well mixed, set aside. Put the rest of the soy sauce into a small pan and add the sherry, sugar, chili sauce, ginger and oil and bring to a boil over medium heat (don’t forget to stir!). Once you reach the boiling point stir the cornstarch soy sauce mixture one more time and add to the pan, lower heat to a simmer and keep stirring until the sauce gets thick. About a minute or so. Turn off the stove and pour into a jar or a container. It can be stored in the fridge for up to one week.
Makes about a cup.