Lay each chicken breast between 2 sheets of clingfilm and flatten with a rolling pin or meat mallet until wafer thin. Season with salt and pepper.
Lay a slice of Parma ham on each chicken breast, followed by a sage leaf. Secure the sage and ham in position with a cocktail stick, then lightly dust both sides of the chicken with flour. Season again with salt and pepper.
Heat the butter and oil in a large frying pan over a high heat, add the chicken and cook for 4–5 minutes on each side or until the juices run clear when pierced with a knife. Add the tomatoes and wine to the pan and bubble until the wine has thickened and reduced by about half. Serve immediately, accompanied by a green salad.