Season the chicken breasts with salt and pepper. Place 2 sage leaves on top of each fillet. Wrap each fillet with 2 slices of smoked ham.
Heat the oil in a pan over medium-high heat. Sear the ham-wrapped chicken for 3-4 minutes on each side until golden brown.
Reduce the heat to medium. Continue cooking until the internal temperature reaches 74°C (165°F), about 5-7 minutes depending on thickness. Remove the chicken from the pan and keep warm.
Pour the Marsala into the pan to deglaze, scraping up any brown bits from the bottom. Stir in the crème fraîche and cook for 1-2 minutes until heated through. Season the sauce with salt and pepper.