A nice pairing with raclette and a Savoie white wine.
In a medium sauce pan combine the apricots, raisins, shallot, wine, water, vinegar, mustard seeds, dry mustard, and salt. Bring to a boil over medium high heat. Lower the heat to a simmer, cover and cook until the liquid is absorbed and the fruit is softened, about 20 minutes.
Uncover and add half the tarragon. Allow to cool. Once the mostarda is cool, stir in the remaining tarragon. Serve or refrigerate for up to 2 days.