Combine all of the ingredients except the butter in a stockpot. Bring to a boil and then reduce to a very gentle simmer.
Cook until the sauce reduces to about one half.
Strain the sauce in a colander to remove the large solids. Restrain through cheesecloth to remove the fine particulates and clarify the sauce.
Return the strained sauce to a clean saucepan and bring to a gentle simmer.
Taste and assess for additional seasoning.
For greater acidity, add a finishing splash of the vinegar.
Whisk in the cold butter until incorporated and serve.