Though a simple enough dish to make, timing, as nearly always when preparing fish, is essential. The first thing is to take sole filets and lay them flat. On top of each filet place a thin slice of prosciutto. Role the layer whole into loose tubes, fish on the outside, and secure them using wooded skewers or toothpicks. Next, peel and seed the tomatoes and hand puree them into a lovely, fragrant pulp.