Place bell pepper wedges, skin sides up, on a foil-lined baking sheet; flatten with hand. Broil 10 minutes or until blackened. Place in a zip-top plastic bag; seal. Let stand 10 minutes; peel.
Heat oil in a large nonstick skillet over medium heat. Sprinkle turkey with sage, salt, and pepper. Add turkey to pan; cook 2 1/2 minutes on each side or until browned. Top each cutlet with 1 bell pepper piece and 2 tablespoons cheese. Add Marsala and broth to pan. Cover and cook 45 seconds or until cheese melts. Remove turkey from pan with a slotted spoon.
Bring Marsala mixture to a boil; cook until reduced to 1/4 cup (about 1 1/2 minutes). Remove from heat; add butter, stirring with a whisk until well blended. Serve with turkey; garnish with sage leaves, if desired.