I’m a big fan of uncomplicated cooking and pickling, which can be summed up as: Vinegar, salt, sugar, soak, is pretty darn uncomplicated.
Pickled mustard seeds have a lovely sharp and bright flavor that helps get me though the long and cold winters around here. I usually use it as condiment with meats or on sandwiches, but do your own thing and what you like best.
There are all sorts of recipes for pickled mustard seeds on the web. The one in the picture came from Food52.com and uses honey and turmeric giving the mustard seeds a warm North African taste.