Preheat the oven to 450 degrees F.
Place the potatoes in a large pot and fill it with cold water. Bring the water to a boil. Simmer the potatoes until they are just barely fork tender. Strain the potatoes and let them cool slightly. (Note: you can do this ahead of time and store the potatoes in the fridge.)
Brush a baking sheet with 1 tablespoon of olive oil. Place the potatoes on the sheet. Use your hand or the bottom of a glass to smash them once, trying to keep them in one piece. Drizzle the remaining olive oil over the potatoes. Sprinkle the potatoes with the salt and pepper.
Place the sheet in the oven and roast the potatoes for 25 to 30 minutes, until golden and crispy. Make the dressing while the potatoes roast. Remove the potatoes from the oven and let them cool slightly. Place the potatoes in a bowl and cover with the dressing, tossing well. Add a few handfuls of extra fresh herbs. Taste and season additionally with salt and pepper if needed. You might need more - this will depend on how seasoned your potatoes are before roasting.
Serve immediately. You can serve this warm or cold - it is your preference. This is best eaten after it is made, but refrigerated leftovers do taste good and you can heat them up too!