Preheat oven to 375 degrees F and adjust the rack to the middle position. Place the green beans and bell peppers in the bottom of a baking sheet or dish. Toss with 2 tablespoons of the duck fat and then season with sea salt and pepper. Wrap 1 piece of prosciutto around each chicken breast and lay them on top of the vegetables. Using a pastry brush, brush the remaining 1 tablespoon of duck fat on the wrapped chicken. Season the meat with sea salt and pepper. Bake for 30-35 minutes, until the chicken is cooked through. Serve.