Creamy potato salad with cheese and prosciutto - Le Coup de Grâce

Ingredients

• 4 cups diced yellow potatoes
• 1 cup finely grated Grana Padano cheese
• 1/2 cup fresh San Daniele or Di Parma prosciutto, white fat removed, finely chopped (about 5 to 6 slices)
• 1/2 cup cooked and cooled corn kernels
• 1/2 cup mayonnaise
• 1/4 cup sour cream
• 1 tablespoon old mustard
• 1 green onion, thinly sliced
• A small handful of fresh parsley, finely chopped
• 4 slices of crispy cooked prosciutto, roughly chopped
• Salt and pepper from the mill