Cut the ciabatta rolls in half, and brush with olive oil. Add some chopped garlic if desired. Lightly toast on a pan on the stove-top over medium heat. Once all the bread is lightly toasted, spread pesto on the top piece of bread. Lay tomato slices on the bottom piece of bread (optional, lightly salt and pepper it) and top with the fresh mozzarella slices. If desired, drizzle on a balsamic glaze. Top with the other ciabatta half and enjoy!