Hasselback Potatoes

1.Arrange a rack in the bottom third of the oven and heat to 425°F. Scrub the potatoes clean and pat them dry.
2.Rest a potato on two chopsticks and cut parallel slits until you hit the chopstick, space the slices 1/8-inch apart.
3.Arrange the potatoes in a baking dish. A small bowl melt the butter then add garlic and olive oil. Mix well and brush the potatoes all over with half the amount.
4.Sprinkle the potatoes generously with salt and pepper. Bake 30 minutes, the layers will start separating. Remove the pan from the oven and brush the potatoes again with the remaining fat — you can nudge the layers apart if they're still sticking together. Make sure some of the fat drips down into the space between the slices.
5.Bake until the potatoes are crispy on the edges and easily pierced in the middles with a paring knife, 30 to 40 minutes. If you're adding any extras, stuff those into the slits and sprinkle over the top 5 to 10 minutes before the end of cooking.