Adapted from adorasbox.net
tbsps. white wine, cider or rice vinegar
tbsps. light soy sauce
tsps. corn flour dispersed in 2 tbsps. water
Caramelize the sugar until medium brown. You may omit this step by using light brown sugar but the caramel gives a nicer flavour to the sauce. Whisk the water, vinegar, soy sauce and ketchup until smooth. Add to the caramel and bring to a boil. Simmer on low heat until the caramel is dissolved. Thicken with the corn flour slurry.