Preheat oven to 425°.
Place potatoes in a pot and cover with salted cold water.
Boil potatoes until done, about 20 minutes.
Line cookie sheet with parchment paper.
Place cooked potatoes on parchment paper and smash with the bottom of a juice glass.
Mix garlic and olive oil (if not using garlic oil) and brush the tops of each potato.
Salt and pepper to taste.
Bake for 30-40 minutes, until crunchy.
Remove from oven and sprinkle grated cheese over each potato. Serve warm.