Place all ingredients in a blender or food processor and puree for a few seconds until smooth.
Pour the mixture into a saucepan and bring to a boil.
Reduct heat and simmer about 20 minutes, whisking often. You may need to adjust the heat as it simmers. You don't want the sugars to burn, but you do want a good bubble happening so that it reduces. The mixture will be ready when it's reduced by about half.