1. Place flour in a shallow bowl and stir in sage. Sprinkle chicken with salt and pepper. Coat each breast with seasoned flour, shaking excess back into bowl. Drape a slice of prosciutto over each side of each breast, overlapping slightly.
2. Warm half of butter and oil in a large skillet over medium-high heat. Carefully add half of chicken, taking care to keep prosciutto in place. Cook until browned on both sides, turning once, 4 to 6 minutes total. Transfer chicken to a plate and cover to keep warm. Repeat with remaining butter, oil and chicken. Serve immediately with lemon wedges on the side.