Preheat oven to 375 degrees F.
Coat pork lightly in flour, brushing off excess. Melt 4 tablespoons of butter in frying pan, add pork and cook quickly 1 minute per side. Remove from pan and continue cooking the remaining pork. Add 3 to 4 tablespoons of cheese to each pork tenderloin and top with 2 prosciutto slices. Bake in oven for 5 to 6 minutes until cheese is bubbling.
In another frying pan, over medium heat, add remaining 4 tablespoons of butter and stir in 2 tablespoons of flour. Cook flour and butter mixture for 1 minute, stirring constantly. Add chicken broth and chopped sage and cook until thickened. Serve over pork tenderloins.
In heavy saucepan, heat oil and deep-fry sage leaves for garnish.
Recipe courtesy of Carissa Seward