Tonkatsu Sosu

From The Japanese Kitchen by Hiroko Shimbo

1/2 c Worcestershire
1/4 c sugar
1/4 c shoyu (soy sauce)
1/4 c ketchup
1 Tb smooth French mustard (check that it's gluten free)
1/3 tea ground allspice

In a small saucepan, combine the first 4 ingredients. Cook over low heat, stirring, until the volume is reduced by 20 percent. Add the mustard and allspice, stirring. Remove the pan from the heat, and let the sauce cool to room temp. Will keep for one week refrigerated in a bottle with a tight fitting lid.