Peel a wide strip from around the middle of each potato. In a kettle combine potatoes and garlic with enough salted water to cover by 2 inches and boil until potatoes are just tender, about 15 minutes.
Drain mixture. Transfer potatoes to a bowl and transfer garlic to a blender. Add to blender lemon juice, oil, and salt and pepper to taste and puree dressing. In the bowl toss potatoes with dressing and parsley. Potatoes may be prepared 4 hours ahead and kept covered.