Peel a head of garlic (you should try this technique … it really works) and chop finely. Place in a shallow bowl of olive oil (about 1/4 cup), add salt and pepper to taste. Let sit so that the flavors get into the olive oil.
Boil the potatoes in salted water for 30 minutes. Place potatoes in cold water afterward until they’re cool enough to handle. One at a time, place potatoes on waxed paper on a hard surface, then press down on them with your hand (you can put a folded dishcloth between your hand and the potato, as shown in the photo). You want to smash them just a little, so that the skin breaks and a few cracks form in the potato … that way the flavored olive oil will get into the cracks.
Turn each smashed potato over with a spatula and brush the top side with the olive oil/garlic mixture. Then, with the spatula, transfer each potato to a baking tray lined with aluminum foil, turning them over again so that the brushed side is down. Spoon more of the olive oil/garlic mixture over the top of each potato.
Roast potatoes in a preheated oven: 400°F for 30 minutes convection or 450°F for 30-35 minutes conventional. Take them out when they start to turn golden and crispy.