In medium bowl, gently toss strawberries and balsamic vinegar; set aside.
Slice bread in half horizontally, place on baking sheet. Arrange cheese slices over bread halves. Bake at 350 F (180 C) for 10-12 minutes or until cheese is melted and starts to bubble. Remove from oven and arrange strawberries on top, sprinkle freshly ground pepper over strawberries. Cut into slices and serve immediately.