Place each breast half, boned side up, between 2 pieces of plastic wrap. Working from center to edges, pound lightly with flat side of a meat mallot to 1/4-inch thickness. Remove plastic wrap. Sprinkle chicken with black pepper. Layer cheese, roasted peppers, and sage in the center of each breast. Fold in sides and roll up, pressing the edges to seal. Roll in flour.
In an 8-inch skillet, cook chicken in hot oil over medium heat about 5 minutes, turning to brown all sides. Remove from skillet. In the same skillet, bring wine or broth to boiling; reduce heat. Simmer, uncovered, about 2 minutes or until 1/4 cup liquid remains. Return chicken to skillet. Cover; simmer for 7 to 8 minutes or until chicken is cooked through. To serve, spoon juices over chicken. Makes 2 servings.
Fontina cheese is a semisoft or firm-textured cheese, depending on its age. It's a bit like Swiss cheese but has smaller holes and a delicate flavor (older cheese may have a fuller flavor).