There are 2 versions of Sweet and Sour Sauce, one with ketchup and one without ketchup.

No ketchup version - 1 tbsp cornstarch, 2 tbsp soy sauce, 3 tbsp balsamic vinegar, 4 tbsp sugar, 5 tbsp water.

Version with ketchup - 1 tbsp cornstarch, 2 tbsp white vinegar, 3 tbsp white sugar, 4 tbsp ketchup, 5 tbsp water.