Put the mustard seeds in a bowl form. Bring the water with the salt to a boil and then pour over the mustard seeds. Soak for half a day. Drain and crush the soaked mustard seeds together with the peppercorns in a mortar. Boil the vinegar and mix in the crushed mustard seeds. This coarse-grained mustard tastes very hearty. The mustard is easy to make and keeps fresh for a while in the refrigerator.
Use it instead of Dijon mustard.