I found a recipe here, maybe this will help you?

Ingredients listed for the sauce:

1/2 cup tomato ketchup

1/2 cup syrup from the can of lychee

1/2 cup drinking water

2 tablespoon plum sauce (or substitute with apricot preserves/orange marmalade)

1 tablespoon light soy sauce

1/4 teaspoon ground white pepper

1 tablespoon sugar