Cut the potatoes into small wedges or chunks. Pat them dry. Place them in 2 large, shallow baking pans and toss each half with 2 tablespoons olive oil and 1 tablespoon rosemary. Salt them lightly. Bake the potatoes for about 30 minutes, turning them with a spatula from time to time and salting them. When they are tender inside and golden brown on the outside, grind fresh pepper over them and serve immediately.