1. Butterfly chicken breasts: with a chicken breast flat on a cutting board and using a sharp knife, cut a deep flap horizontally through the meat, being careful not to cut all the way through. Open chicken breast like a book. Repeat with the remaining breasts.
2. Top one side of each the butterflied chicken breasts with 1 slice prosciutto, 2 sage leaves, and a handful of cheese. Fold over other half of chicken breast and secure the two halves together using 3 toothpicks. Season both sides of chicken liberally with Kosher salt and freshly ground pepper.
3. Heat 2 tablespoons of the oil in a dutch oven or other oven-safe heavy bottomed skillet over medium/medium-high heat. Add chicken to pan and cook for about 6 minutes, until a golden brown crust has formed. Flip chicken over and place in a preheated 400°F oven until cooked through (165°F internal temp for those using thermometers), approximately 25-30 minutes.
4. While chicken is roasting in the oven, heat up the remaining two tablespoons of oil in a small frying pan over medium heat. Once hot (the prosciutto should sizzle as soon as it hits the oil), fry the other 4 slices of prosciutto, one at a time, until golden brown, approximately 30 seconds - 1 minute per side. Drain on a paper-towel lined plate.
5. Top your roasted chicken breast with orange-sage vinaigrette and a slice of fried prosciutto. Serve immediately.

for the Orange-Sage Vinaigrette

1. Combine white wine vinegar, orange zest, sage, and garlic in a food processor or blender until smooth. With motor running if possible, drizzle in oil and blend until mixture is emulsified. Season with Kosher salt and freshly ground black pepper to taste.