Roast coriander seeds in a frying pan without oil. Grind the mustard and coriander seeds in a mortar or spice grinder.
(I misused an electric coffee grinder specifically for spices.) Mix the finely crushed grains into the water and let stand for 3 hours. Then mix all ingredients in a hand mixer until smooth.
Bring the mixture to a boil in a saucepan and simmer over low heat for at least 5 minutes to thicken. Always stir well. Transfer to sterilized jars.
Info: Jalapeno chilies are medium hot. If you can’t find any, you can also use the Dutch/Spanish peppers from the supermarket.
Habanero Chilis touched. Hellishly hot !
Tip: Stock up on a range of high quality spices – it pays off!