In a medium saucepan, combine all ingredients and whisk to combine. Cook over medium heat until the mixture comes to a boil, then reduce heat and simmer for 25 minutes.
Transfer to a lidded jar and chill in the refrigerator. I recommend letting the sauce sit in the fridge overnight before using to really marry the flavors together. This sauce will last 2 weeks in the fridge if stored in an airtight container.