Whisk together all of the ingredients in a medium pot. Set over medium heat and bring to a boil. Reminder that it is already a reasonably thick sauce and when it starts to boil it may splatter a bit, both messy and mildly painful if it lands on your hand.
Turn down to low and simmer, partially covered (for splatter), for about 30 minutes, or until it gets to close to the consistency you like.
If you will be storing in a glass or ceramic jar, transfer while still warm and then chill the storage container in an ice bath (lid off, so be careful not to spash water into the jar). If you will be storing in a plastic container, allow to cool to room temperature before transfering.