Mustard seeds by John Spottiswood.

Mustard seeds have a hot, pungent flavor. Yellow mustard seeds are the ones you'll most likely find in American and European kitchens. They're often ground and made into prepared mustard or added to stews and sauces to give them some zip. Indian cooks usually prefer the smaller and more pungent brown mustard seeds or black mustard seeds . When recipes call simply for mustard, they may be referring to prepared mustard , the condiment we like to put on hot dogs. When crushed, mustard seeds are very pungent, but Indian cooks fry them in oil, which makes them sweet and mild.