Put the potatoes in a large saucepan and cover with water by at least one inch.  Add 2 teaspoons salt and bring to a boil.  Reduce the heat so that the water is simmering, and cook the potatoes until a knife inserted into the potatoes meets no resistance (about 30-35 minutes.)  Remove the potatoes from the pot and let drain briefly on a double layer of clean dishtowels.  Take another clean dishtowel, fold it into quarters and, using it as a cover, press down firmly on one potato with the palm of your hand to flatten it to about ½-inch thick.  Repeat with all the rest of the potatoes. Cover a large rimmed baking sheet with aluminum foil and put parchment paper on the foil.  Carefully move the potatoes to the prepared baking sheet, then allow them to cool.

While the potatoes are cooling, preheat the oven to 450° F (400° F for a convection oven.)  Sprinkle the potatoes with about ¾ teaspoon salt and drizzle with the olive oil, lifting each potato to allow some of the oil to get underneath. The potatoes should be well coated with the oil on both sides.  Roast the potatoes until they are brown and crispy, about 30 minutes, turning over halfway through roasting.  If using a conventional oven, the roasting time may increase slightly.  Serve immediately.