Combine the mustard seeds, wine and vinegar in a glass measuring cup. Cover with plastic wrap and let sit at room temperature for two days. Transfer the contents to a blender along with the salt and honey. Blend until you achieve the desired consistency, anywhere from 30 to 60 seconds. Store in a glass jar with a tight fitting lid and refrigerate another 2 hours before serving. Makes about 1 cup.
Mustard will keep in refrigerator for a couple of months as long as it's tightly covered.