Use A Knife Or Grater To Sharpen The Thick Ends Of The Rosemary Sprigs. Soak Sprigs In Water For At Least 10 Minutes. Preheat Oven To 425 Degrees F (220 Degrees C). Layer Each Chicken Breast With 1 Slice Fontina And 1 Slice Prosciutto. Roll Tightly, And Skewer Each With A Rosemary Sprig To Secure. In A Bowl, Whisk Together The Wine, Broth, Oil And Pepper. Pour Into A Medium Baking Dish. Place Rolled Chicken Breasts In The Dish. Place 2 Garlic Halves Under Each Breast. Bake 25 Minutes In The Preheated Oven, Until Chicken Juices Run Clear. Remove From Baking Dish, Reserving Sauce, And Allow To Stand 5 Minutes. Transfer Remaining Sauce To A Saucepan, And Bring To A Boil. Drizzle Over Chicken To Serve. Season Chicken With Salt To Taste.