For the paste, place the capers, garlic and olive oil in a mortar and grind with a pestle to make a paste.
For the sole, line up the slices of prosciutto on a clean work surface, well spaced apart.
Place one sole fillet on each slice of prosciutto, brush the fish with a light layer of the caper paste, then top with a sprig of parsley. Season with salt and freshly ground black pepper, to taste.
Carefully roll up each fillet in the prosciutto slice and tie to fasten using a chive.
Line a baking tray or an ovenproof dish with greaseproof paper and place the wrapped and rolled fish fillets on the dish. Bake in the oven for approximately 10-15 minutes, or until the fish is just cooked.
For the sauce, heat the olive oil in a small frying pan and add the bay leaves, shallot, garlic and parsley. Fry on a medium heat for about seven minutes, or until the shallot has softened.
In a small bowl, whisk together the wine and cornflour. Add the cornflour mixture to the pan. Stir well and season to taste with salt and freshly ground black pepper. Cook for a further five minutes, or until the sauce has thickened.
Remove the sole fillets from the oven and transfer them to a large serving dish, or onto four individual plates, and pour over the sauce before serving. Serve with the boiled baby potatoes.