1. Preheat oven grill to 200C.
2. Put the potatoes in a pot with water and salt. Boil the potatoes for about 5-8 minutes. Take up the potatoes, dry them and let them cool.
3. Roll each potato in a prosciutto slice and lay them in an ovenproof dish with red onions. Drizzle with olive oil and sprinkle with salt and pepper. Grill the potatoes for 20 minutes.
4. Cut the Castello® Double Cream Chilli cheese into smaller triangles
5. Mix rosemary syrup and white wine vinegar and brush it over the potatoes (save a little of the mixture) and grill for another 10 minutes.
6. Spread the cheese on top of the potatoes - let the cheese roast with the gratin the last 4 minutes. Serve with the rest of the syrup.
7. Serve with grilled meats, such as chicken or steak.