Put the halved chicken breasts between 2 sheets of wax paper and flatten them until they are 1/2 inch thick.
Arrange the breasts, skin side down, and sprinkle them with salt and pepper. On each half put 2 paper thin slices of prosciutto and 3 paper thin slices of Mozzarella cheese. Turn sides of breasts over the filling, roll them and secure ends with picks.
Dust the breasts with flour seasoned with salt and pepper; brown on all sides in hot olive oil over moderately high heat.
Transfer with a slotted spoon to an ovenproof dish. Remove oil from pan and add wine; reduce the wine over high heat, scooping the brown bits that cling to the bottom of the pan, for 1 minute, then add the fresh tomato sauce, oregano, salt and pepper to taste. Simmer for 2 minutes; pour the sauce over the chicken breasts and bake at 350 degrees for 15 minutes. Garnish with fresh parsley.
