Pre-heat oven to 450° F and position the middle rack.Line a baking sheet with parchment paper or tin foil.
Rinse the potatoes and place them into a large bowl.
In a small bowl, whisk the grated garlic into the olive oil. Drizzle the garlicky olive oil over the potatoes. Add the chopped fresh rosemary, and a sprinkle of coarse salt and cracked pepper, to taste. Toss to coat.
Transfer the potatoes onto the covered baking sheet and bake for 20-25 minutes, or until the potatoes have started to turn golden brown in color. When this happens, remove the baking tray from the oven and set it somewhere safe. Turn the oven to broil and move the rack one slot higher.
Carefully press down on each potato with a flat surface (bottom of a plate, bowl, or large mug) to smash it. Place the baking sheet back into the oven and broil the potatoes for a few more minutes, just until the edges crisp up nicely. Broilers vary, so keep a close eye on your potatoes.
Once the potatoes have crisped up, remove them from the oven and set aside to cool a bit. Once cooled, grate cheese over each potato and sprinkle with a bit more coarse salt and cracked black pepper—then serve!