These red skin mashed potatoes are creamy, buttery, and homestyle, with no peeling needed. Red potatoes give the mash a naturally rustic texture, while sour cream adds richness.
Scrub the red potatoes well and cut out any eyes, bruises, rough spots, or green areas. Cut the potatoes into evenly sized 1 to 1 1/2-inch chunks. Leave the skins on for a rustic texture.
Place the potatoes in a 5-quart Dutch oven or large pot. Cover them with cold water by about 1 inch, then add 1 tablespoon salt to the water.
Bring the potatoes to a boil over medium-high heat. Reduce the heat and simmer for 15 to 20 minutes, or until the potatoes are very tender and a fork slides through easily.
Drain the potatoes well, then return them to the hot pot. Set the pot over low heat for 1 to 2 minutes, gently shaking or stirring the potatoes, to help steam off extra moisture.
While the potatoes are drying, warm the butter and milk together in a small saucepan or microwave-safe bowl until the butter is melted. Do not boil.
Mash the potatoes by hand with a potato masher. Pour in the warm butter and milk mixture a little at a time, mashing gently until the potatoes are creamy but still rustic.
Stir in the sour cream.
Season with kosher salt and black pepper. Taste and adjust as needed. Serve warm with extra butter, gravy, or fresh herbs if desired.