Season the veal with salt and pepper; cover with the prosciutto. Top with the sage leaves; secure them by weaving in a toothpick horizontally (see photo, right). Place the flour on a plate, add the veal and turn to coat; shake off any excess.
In a large skillet, heat 2 tbsp. butter and the EVOO over medium- high heat until foaming. Working in batches, add the veal and cook, turning once, until browned and crisp, about 3 minutes. Transfer to a plate. Deglaze the pan with the wine. Stir in the remaining 2 tbsp. butter to melt and thicken the sauce.
To serve, spoon the pan sauce over the saltimbocca.