Arrange the flour in a shallow dish. Dip each chicken cutlet into the flour and coat evenly, then shake off the excess and arrange the cutlets on a chopping board.
Gently layer a slice of Parma prosciutto onto each cutlet, top with a sage leaf and secure with a cocktail stick.
Heat the extra-virgin olive oil in a large nonstick frying pan over medium heat. Add the chicken cutlets in a single later, ham (prosciutto) side down. Sear the chicken cutlets for 2 minutes, until the bottom is colored and crispy.
Flip the chicken cutlets, and season with pepper. Continue searing for 3 more minutes, until the bottom is browned and the chicken is cooked through. Remove from the pan and arrange the chicken saltimbocca on a plate and cover with foil to keep warm.
Add the butter to the pan and cook until foamy. Pour in the wine and shake the pan vigorously until the sauce reaches a velvety consistency. Divide the chicken saltimbocca between the four plates, pour the sauce on top and serve immediately.
For the traditional version. substitute the chicken with the veal.For stronger flavors, substitute sage with rosemary sprigs.