Pound scallopini between pieces of plastic wrap until thin. Top each of the slices with a slice of prosciutto and a sage leaf. Secure prosciutto and sage leaf to the veal with a toothpick. Melt the butter in a pan large enough to accommodate the 4 veal slices and brown them on both sides for a few minutes. Sprinkle with fresh pepper and lightly with salt (prosciutto is already salty). Add white wine and reduce quickly over high heat until almost glazed. The whole procedure should not take longer than 5 minutes. Serve with "instant" polenta and/or saute of mushrooms and parsley.