01 -
Rinse the potatoes and scrub them clean. Fill a big pot with water, sprinkle in a few pinches of salt, and bring it to a rolling boil. Pop the potatoes in and let them cook for 20 minutes or so until they're soft enough for a fork to slide in easily. Drain, rinse with cold water, and peel them if you'd like. Dice them into bite-sized chunks.
02 -
Chop the radishes into thin slices and cut the green onions into small pieces.
03 -
Grab a small bowl and mix the sour cream, olive oil, lemon juice, and a bit of kosher salt until smooth.
04 -
Pour the dressing over the potato pieces, then sprinkle on black pepper to your liking. Mix it all up and have a taste—add more lemon juice or salt if needed. Serve it at room temp immediately. If you're saving some for later, let it come to room temperature before eating and add an extra squeeze of lemon juice and a pinch of salt.