Heat the oven to 450°F with a rack in the lower-middle position.
Scrub the potatoes clean and pat them dry.
Cut slits into the potato, stopping just before you cut through so that the slices stay connected at the bottom of the potato. Space the slices 1/8-inch to 1/4-inch apart. You can rest the potato in a large wooden serving spoon or in between two chop sticks to use as a guide, slice straight down and when your knife hits the edge of the spoon or chopstick, stop slicing.
If using smaller potatoes leave them whole, before slicing. If using larger potatoes you can cut them in half crosswise, turning them and making slices on the round side.
Place the cut potatoes in a bowl of salted water. This can be done up to 24hrs ahead. Just make sure to thoroughly dry the potatoes before baking. Soaking them for at least 1-24hrs helps the slices open up.
Heat desired fat, (a mixture of butter and olive oil works well) with crushed garlic cloves, just until fragrant. Infusing the fat with garlic makes the potatoes extra tasty, however the garlic is optional.
Arrange the potatoes in a baking dish and brush the potatoes all over with 1/2 of the infused fat, including the bottoms.
Sprinkle the potatoes generously with salt and bake 30 minutes.
At this point you can add your favorite herbs to the remaining fat, and brush the potatoes again, saving a bit for the end, and bake for another 30-45 minutes you will notice the layers start separating.
Remove the pan from the oven and brush the potatoes one last time with the last little bit of fat. Make sure some of the fat drips down into the space between the slices.
Bake for another 10-15 minutes, until the potatoes are crispy on the edges and easily pieced in the middles with a paring knife. 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. (Total baking time is 60 to 90 minutes for average potatoes. Adjust cooking time accordingly depending on the size of the potatoes you are using.
These potatoes are best straight from the oven while the edges are at their crispiest.
This impressive and yet simple method of creating several deep slices all across the spuds, increases the surface area and once exposed to the oven’s high heat you get lots of crispy edges, while the inside remains soft and creamy.