To make rustic chicken stock mashed potatoes with sour cream and chives, start by washing about two pounds of potatoes thoroughly, leaving the skins on for a more rustic texture. Yukon Gold or Russet potatoes work well. Place them in a large pot and pour in two cups of low-sodium chicken stock along with one cup of water, making sure the potatoes are mostly covered. Bring the pot to a boil, then reduce the heat and let the potatoes simmer until they are fork-tender, which usually takes about fifteen to twenty minutes. Once they are cooked, drain them carefully, reserving a little bit of the cooking liquid. Return the potatoes to the pot or transfer them to a large bowl and mash them to your preferred consistency using a potato masher or a hand mixer.
Stir in three tablespoons of unsalted butter until it melts completely. Add half a cup of sour cream and, if you prefer a creamier texture, a splash of whole milk or cream. If the mashed potatoes are too thick, loosen them with a bit of the reserved cooking liquid until you reach the texture you like. Season with salt and pepper, then fold in about two tablespoons of finely chopped fresh chives. You can also add a pinch of nutmeg or a little garlic powder—or even roasted garlic—if you want extra depth of flavor.
Serve the mashed potatoes warm, with more chives or a small pat of butter on top if you want to dress them up. Using chicken stock in the cooking liquid gives the potatoes a gentle savory richness, while the sour cream adds a creamy tang that brightens the dish. Leaving the skins on keeps their texture hearty and helps retain nutrients, and the fresh chives add mild onion flavor and a pop of color.