Italian Chicken with Pesto Potatoes

Preheat oven to 400 degrees F (200 degrees C).

In a saucepan, bring the vinegar to a boil. Reduce heat, and simmer 15 minutes, stirring frequently, until thickened.

Cut a pocket in each chicken breast. Fill each pocket with an equal amount of mozzarella cheese, and season with salt and pepper. Wrap each chicken breast with a slice of ham. Arrange the wrapped chicken breasts in a baking dish. Place the tomatoes around the chicken, sprinkle all with olive oil, and season with salt and pepper.