You have been warned: I told you that I would be making my own mustard, and I have. I had one failed attempt by following a recipe from the Internet (the result was bitter tasting), so I made-up my own:
1 cup of yellow mustard seeds
Soak seeds in cold water over night, then drain the seeds. Put some nice white vinegar (Cider?) into a saucepan. You need approximately one fifth of the drained seeds’ volume. Use less vinegar when in doubt. Heat up to some medium temperature (50C?), melt a large tea spoon of honey in the vinegar. Remove from heat. Add ground black pepper, 1/4 teaspoon of salt, 1/4 teaspoon of tarragon leaves, one tablespoon of balsamic vinegar.
Put everything into the blender and blend until smooth. Add Balsamico or white vinegar if more liquid is needed. Transfer into an empty jar with a good lid, and let set in the fridge over night. Done.
This has a lot of room for variation. Which is yours?