Wash potatoes them and boil in a pot of salted water for 20 minutes, or until tender enough to slide your fork into the biggest one easily.

Meanwhile, preheat your oven to 450

Spray a baking sheet with cooking spray and place the potatoes on it.

Drizzle olive oil over the tops, then using a fork or a potato masher, gently smash them down until the skins pop open.

Brush some more olive oil over the craggy tops of each potato.

Sprinkle a little sea salt over each potato, then spoon a little Parmesan cheese, and follow with rosemary and a little garlic on each as well.

Bake near the top of the oven for about 20 minutes - check on them and put them back in for another 5 if need be. (You want the skin to be crispy and the little crags and points to have a crunch as well.)