Finely grind the mustard seeds. Mix with 100 ml (approximately 3 ounces) of water and soak for 1 hour. Rinse and dry the herbs, then finely chop. Add the white wine and balsamic vinegar to a saucepan. Add the salt, sugar, and peppercorns, and bring to a boil briefly. Mix in the chopped herbs, and let cool. Add the mustard mixture, and mix well. Gradually incorporate the oil, until a thickened sauce forms.
Transfer the mustard into bottles. Refrigerate until ready to use. The mustard is good for 3-4 weeks.