Combine everything except the Dijon in a small, heavy saucepan. Bring to a simmer then lower heat and cook until reduced to a thick puree with the consistency of ketchup, about 1 hour over low heat. Stir in the Dijon off the heat and season if needed.
Crush the cherries with a potato masher or pulse in a blender or food processor if you prefer a smoother texture.
Keep in a covered jar in the refrigerator for about 2 weeks.