Chocolate Chili Barbecue Sauce

Straight from Hershey Pennsalvania,
here is a recipe for chocolate BBQ.
The inventors of this sauce used it
on beef tenderloin and scallops recipes,
it works just fine as a regular barbecue sauce.

Ingredients:
4 ounces of apple cider vinegar
8 ounces of your favorite barbecue sauce
14 ounces of vegetable stock
1 tablespoon butter
1/2 onion, diced small
2 Roma tomatoes, diced small
2 tablespoons chopped fresh cilantro
4 minced garlic cloves
2 teaspoons brown sugar
4 teaspoons chili powder
1/4 teaspoon ground cumin
1/4 teaspoon ground cinnamon
1/8 teaspoon ground cloves
3/4 teaspoon salt
1/2 teaspoon ground black pepper
2 ounces dark chocolate

Directions:
Melt butter over medium heat in a saucepan,
add the onion and garlic, saute for five minutes.
Stir in the tomatoes, and continue sauteing
for five more minutes before
adding the sugar and chili powder.
Mix it thoroughly, then cook it
for five more minutes. Next,
reduce the mixture in the vinegar
until it has a pasty consistency.
At that point, add in everything else
except the cilantro and chocolate,
and bring it all to a boil after mixing well.
Then lower the heat and
let it simmer for half an hour.
Finally, add the cilantro and chocolate,
and let the mix simmer for another
five minutes before removing it from
the heat and letting it stand for ten minutes.
Then puree the sauce in a blender,
and pour it into a container to cool.
Refrigerate for at least 12 hours before use.