Mustard is crazy easy to make. It’s so easy we don’t buy mustard in our house anymore. We just make it. It takes few days, so a little planning is needed, but not a whole lot of attention or active time is called for.
(Tangent: According to Wikipedia, mustard is “commonly paired with,” among other things, pizza and sushi. That’s wrong on so many levels…)
The recipe below is a very basic recipe. It works fine on its own, but use it as a starting point for experimentation. Play around with the ratios of mustard seed (the brown is spicier than the regular yellow), add some dried tarragon, throw in some honey or brown sugar, or try red wine or a splash of bourbon. The only thing I would caution against experimenting with is the ratio of liquid. Nobody likes runny mustard.
The finished mustard will be bitter, but let it sit for a day or two and that will dissipate.
Combine all ingredients and let sit for two days. Blend to desired consistency. Refrigerate for a day or two before using to allow bitterness to dissipate.