Optionally, you could choose to use melted butter instead of garlic olive oil. Also, I chose to keep the skin on the potatoes since it is healthier and tastier.
Preheat oven to 425 degrees.
Place potatoes into a large wooden or metal spoon. Using a sharp knife, make slices across the potato the short way about 1/8 inch apart, making sure to cut down to the lip of the spoon, not all the way through the potato. The slices should stay connected at the bottom, and the spoon helps keep the depth even. Place the potatoes in a bowl of water, and proceed with the remaining potatoes.
Drizzle the potatoes with garlic olive oil and sprinkle with coarse salt.
Bake in preheated 425 degree oven for 30-45 minutes, or until potatoes are done all the way through.
Serve with sour cream and green onions, if desired.