How to Make It
Place potatoes in a large pot. Add water to cover by 1 inch, and bring to a boil over medium-high. Add 2 tablespoons salt, reduce heat to medium, and simmer until tender, 25 to 30 minutes.
Meanwhile, combine caraway seeds, coriander seeds, and fennel seeds in a small skillet. Cook over medium, stirring constantly, until spices are very fragrant, toasted, and seeds begin to pop, about 5 minutes. Transfer to a mortar, and crush with a pestle. Stir together crushed seeds and olive oil in a medium bowl until well combined.
Drain potatoes, and cut in half lengthwise. Place a wire rack over a large bowl. Working in batches, place potato halves, cut side down, on rack, and press through until only the skin remains; discard skins. Fold spiced olive oil into potatoes; gently stir in pepper and remaining 1 tablespoon salt. Serve warm or at room temperature.