Heat the olive oil in a large, heavy skillet over high heat. When it is very hot, add the potatoes. Cook for 10 minutes, turning frequently with a metal spatula, until they are light brown on all sides. If there is quite a lot of oil remaining in the pan, drain off and discard some of it. Scatter the onion, garlic, salt and pepper evenly over the potatoes and pour in the boiling water and the wine. Do not stir, but instead shake the pan back and forth for a minute to distribute the water evenly.
Cover the skillet and turn the heat to low. Simmer for about 20 minutes, or until the potatoes are tender but not mushy. Shake the skillet back and forth occasionally to stop the potatoes from sticking. Three minutes before the potatoes will be done, stir in the parsley. With a slotted spoon, transfer the potatoes to a warm serving platter and pour some of the cooking juices over them. Pass the remaining cooking juices, if desired.