Preheat the oven to 180 degrees Celsius, 356 Fahrenheit. Grease a large baking dish with olive oil and line a large baking sheet with parchment paper.

Place a potato onto the chopping board and make thin slices into the potato across the whole length of the potato and not more than halfway through the potato, being careful not to cut all the way through.

Repeat this step with remaining potatoes and place the sliced potatoes, sliced side up, into the baking dish.

In a small bowl, mix together the onion powder, garlic powder and salt. Sprinkle over the top of the potatoes. Drizzle the potatoes with olive oil and use a pastry brush to evenly coat all of the potatoes with the olive oil and seasoning.

Place the tray into the oven and bake for 1 hour and 15 minutes.

While the potatoes are baking, prepare the prosciutto crumb. Place the thin slices of prosciutto onto a baking tray. Place into the oven on the top shelf for 10 minutes. After 10 minutes, remove from the oven and allow to cool to touch.

Add the baked prosciutto slices and fresh parsley into the food processor and pulse until you reach a crumb consistency. Turn out onto the parchment paper lined baking tray and place back into the oven for 5 minutes to dry out. Remove from the oven and set aside until the potatoes are baked.

Once the potatoes are baked, remove from the oven and serve hot topped with the prosciutto crumb.