1. Put wine, onion, and garlic in small saucepan and heat on medium high heat until mixture just comes to a boil, then turn heat to low and simmer slowly for 5 minutes.
2. Remove and pour through strainer into a large saucepan and set aside to cool.
3. When wine mixture is cooled down, set back on low burner and slowly start adding mustard to saucepan, whisking constantly.
4. When mustard is all incorporated and smooth, start adding the remaining ingredients, whisking constantly.
5. Continue heating all ingredients together over low heat, stirring constantly until the mixture gets thick.
6. Store in glass jars with tight lid in the refrigerator. This mustard is best after it has chilled for several days.