Position a rack in the center of the oven and preheat to 425 degrees . In a large bowl, combine the olive oil, garlic, 1/2 tablespoon salt and 1/4 teaspoon pepper. Add the potatoes and toss to coat. Arrange the potatoes in a single layer on 2 large rimmed baking sheets. Pour a little water into each pan and bake for 30 minutes. Toss and bake for 15 minutes more.
Lower the heat to 350 degrees . Transfer the potatoes to paper towels to drain. Wipe the baking sheets dry, line with parchment paper and return the potatoes to the baking sheets in a single layer. Bake until golden-brown and crisp, 15 to 20 minutes. Toss with the parsley.