I'm a big fan of adding mustard to my mashed potatoes to give it a little bit of an edge. My inspiration to add miso came while I was having an amazing sushi dinner on Saturday night. A little sugar and a little miso paste seemed to tone down the sharpness of the mustard, yet make it even richer at the same time. I tried to recreate it at home and wasn't disappointed. —theicp
Clean and chop the potatoes, leaving the skins on but there are no imperfections on the potatoes, and boil in salted water for 20 - 25 minutes.
Drain the potatoes through a colander and return them back to the pot to mash them. After they're sufficiently mashed, stir in the butter, milk, and some hefty pinches of salt. These should taste like your average, dinner time mashed potatoes.
Once the potatoes are smooth and the taste is to your liking, stir in the mustard miso sauce. Make sure the sauce is thoroughly mixed in the potatoes and serve. (Sprinkle some green onions or chopped cilantro on top if you're in the mood for garnish.)
Mustard Miso Sauce
Simply combine in a small bowl and whisk together until smooth.