Combine the tomatoes, tarragon, salt, cayenne, garlic, vinegar, and wine in a saucepan over medium-high heat. Bring to a boil. Reduce the heat to medium and simmer for 20 to 25 minutes, or until the mixture is dark brown and thick. Remove from the heat and add the parsley. Let cool.
Add the mixture to the hollandaise and whisk together until well blended.
Choron can be made ahead and stored in the refrigerator, covered, for up to 3 days.
Yield: 1 1/2 cups