Step 1

Season the chicken with salt and pepper. Place 2 sage leaves on each breast. Top with a slice of prosciutto, trimming it to fit. Press the prosciutto to help it adhere to the chicken. Dust the chicken with flour, shaking off the excess.

Step 2

Heat a large skillet. Add the oil and 2 tablespoons of the butter. Add 2 of the breasts, prosciutto side up, and cook over high heat until nearly cooked through, about 3 minutes. Turn the chicken and cook just until the prosciutto begins to shrink, about 1 minute. Transfer the chicken to a plate; repeat with the remaining chicken. Pour off any fat and wipe out the skillet.

Step 3

Add the remaining butter to the skillet. Add the wine and cook over high heat until reduced by half, 2 minutes. Add the stock and bring to a boil. Cook until reduced by half, 3 minutes.

Step 4

Return the chicken to the skillet, prosciutto side up, and simmer over moderate heat until the chicken is cooked through, about 2 minutes; season with salt and pepper. Transfer the chicken to plates, pour the sauce on top and serve.