In a fry pan on medium heat add Oil, and 1/2 the Butter, allow to get hot. Add Chicken, sauté for five minutes on each side, (until golden brown on each side). Remove Chicken, set aside on a clean dish.
In the same fry pan, add the remaining Butter, and 18 g of Flour. Stir constantly for 2 minutes. Reduce heat to medium low, then pour in the Wine. Mix until Sauce has thickened.
Pour in the Chicken Stock, mix until fully combined. Place Chicken back into the frying pan. Let simmer covered for 2 minutes.
Place a slice of Prosciutto on top of each Chicken piece, then top with Cheese.
Cover the pan with a lid and allow to simmer for 6 minutes, until the Cheese has melted.
Serve.