1/3 Cup all-purpose flour
1 teaspoon ground black pepper
8 thin-cut, boneless, skinless chicken breast cutlets (about 2 pounds), trimmed of ragged edges as necessary
1 tablespoon minced fresh sage leaves ,
8 thin slices prosciutto , cut into 5- to 6-inch-long pieces to match chicken (about 3 ounces)
4 tablespoons olive oil
11/4 cups dry vermouth or white wine
2 teaspoons juice from 1 lemon
4 tablespoons unsalted butter , cut into 4 pieces and chilled
1 tablespoon minced fresh parsley leaves
1 teaspoon salt
1. Adjust oven rack to middle position and heat oven to 200 degrees. Combine flour and 1 teaspoon pepper in shallow dish.
2. Pat cutlets dry with paper towels. Dredge chicken in flour, shaking off any excess. Lay cutlets flat and sprinkle evenly with minced sage. Place 1 prosciutto slice on top of each cutlet, pressing lightly to adhere; set aside.
3. Heat 2 tablespoons oil in 12-inch skillet over medium-high heat. Add half of cutlets to pan, prosciutto-side down, and cook until light golden brown, 2 to 3 minutes. Flip and cook on other side until light golden brown, about 2 minutes more. Transfer to baking sheet and keep warm in oven. Repeat with remaining 2 tablespoons oil and cutlets, then transfer to oven to keep warm while preparing sauce.
4. Pour off excess fat from skillet. Stir in vermouth, scraping up any browned bits, and simmer until reduced to about 1/3 cup, 5 to 7 minutes. Stir in lemon juice. Turn heat to low and whisk in butter, 1 tablespoon at a time. Off heat, stir in parsley and season with salt and pepper. Remove chicken from oven and place on platter. Spoon sauce over cutlets before serving.