Instructions
Follow the steps and taste along the way.
Boil the potatoes
Wash the potatoes, place them unpeeled in a pot, and cover with cold water. Simmer gently for 20–25 minutes, until a knife slides into them easily.
Prepare the accompaniments
Drain the potatoes and leave them to steam-dry for 5 minutes. While they cool, finely chop the onion, chop the chives, and slice the radishes into thin rounds.
Mix the spread
While still warm, peel the potatoes and mash them with a fork into a coarse mash, leaving some small pieces. Mix in the butter, then the sour cream, onion, chives, caraway seeds, salt, and black pepper. Stir and taste; the spread should be mildly tangy and noticeably salty.
Toast the bread
Toast the rye bread slices in a dry pan over medium heat for about 1–2 minutes per side, until crisp on the outside but still soft in the middle.
Serve
Divide the spread over the bread and serve warm or at room temperature with the radishes. If you made it ahead and it has chilled, let it stand at room temperature for about 10 minutes before serving.
