Mustard is so very easy to make and the perfect addition to a ham sandwich. It makes a great homemade gift too.
Mix the mustard seeds and beer together in bowl, cover and set aside overnight. (The mustard seeds will soften and soak up most of the beer.)
Sterilise the jars for the mustard. Wash in very hot water or on the hot cycle of a dishwasher. Preheat the oven to 160C/325F/Gas 3. Place the jars upside down on a baking tray and dry in the oven for 10-15 minutes.
Stir in the remaining ingredients, then blend in a food processor until nearly smooth (you may need to do this is batches).
Spoon the mustard into the sterilised jars; tap gently to remove all the air bubbles.