This is taken from Real Chocolate cook book. Chantal Coady of http://www.rococochocolates.com/ in London wrote this book.
She says "I have found this little invention totally invaluable. As well as its obvious uses, say in salad dressings and deglazing pans to make gravies and sauces, you will see it delivers the chocolate element in lots of my savoury recipes. It does, though, also lend itself to dishes other than savoury - just try it over fresh strawberries. For a more piquant version to use with red meat and cheese dishes, like Welsh rabbit, add 100ml Worcestershire sauce.
Chocolate Balsamic Vinegar
1oog white caster sugar
100 ml vinegar (I used equal parts cider and cooking balsamic)
30g grated real dark chocolate (at least 70%)
Gently heat the sugar and vinegar in a small deep pan until all the sugar has dissolved, then allow to bubble gently for 5 minutes.
Take off the heat, whisk in the chocolate well and leave to cool. When cool, stir again quickly. Pour into a small clean jam jar to store until needed.
(I warm it in the microwave for a few seconds, with the lid off, until I have a liquid consistency).
I have made fresh pasta and filled it with cooked potatoe and fried brown onion (until it's really browned and caramelised) like a ravioli and drizzled this sauce over it, some grated parmesan and toasted pinenuts and my vego friends have LOVED this recipe. Also last weeks pizza recipe as I showed you.