Rob's Rib Sauce

2 cups coke cola

2 cups ketchup

1/2 cup cider vinegar

1/2 of a large onion finely chopped

1 1/2 TB black pepper

1/4 cup brown sugar

3 tsp salt

3 TB chilli powder

2 TB minced garlic

2 TB Dijon mustard or 1 tsp dried mustard

2 TB butter

Bring all ingredients to a boil. Reduce heat and simmer for one to two hours, stirring occasionally.