Using a meat mallet, lightly POUND each chicken breast half until it is 1/8- to 1/4-inch thick.
LAYER two slices of prosciutto and cheese (see note 3) on each breast (if too thick to roll tightly, reduce to a single layer).
Tightly ROLL up (like a jelly roll) each breast lengthwise, securing with toothpicks.
In three shallow bowls, MIX flour, salt and pepper in first; MIX eggs and milk in second; PLACE bread crumbs in third.
DREDGE rolled breasts in seasoned flour, then beaten egg, then bread crumbs.
HEAT oil and butter in a large skillet; PLACE breasts in skillet and SAUTE at 325F for 20 minutes, TURNING frequently.
Meanwhile, prepare sauce by doing the following: aMELT the butter in a small saucepanbSTIR in mushrooms and garlic; COOK until tendercSTIR in flour and nutmeg; ADD milk all at once; dCOOK and STIR until thick and bubblyeCOOK and STIR two minutes more; STIR in sherry.
TOP chicken with a fresh parsley, oregano, or thyme garnish and SERVE with sauce on the side.
1. For the best serving size, use chicken breasts of 5-6 ounces apiece. 2. Prosciutto may be found at the deli counter. 3. If sliced correctly, the prosciutto and the cheese should each weigh less than 1/2 ounces per slice; if more, use only one slice each per breast.
Per Serving (excluding unknown items): 2211 Calories; 116g Fat (48.3% calories from fat); 228g Protein; 51g Carbohydrate; 2g Dietary Fiber; 670mg Cholesterol; 13858mg Sodium. Exchanges: 2 1/2 Grain(Starch); 30 Lean Meat; 0 Vegetable; 1/2 Non-Fat Milk; 9 1/2 Fat.