1 tbsp olive oil
salt and pepper
3 plum tomatoes thinly sliced
12 slices (about one log) of mozzarella
1/2 cup (or about 12 leaves) fresh basil
1/2 cup balsamic vinegar
1 tbsp dark brown sugar
Preheat oven to 400 degrees F. Rub each chicken breast with olive oil and season with salt and pepper. Make deep slices horizontally into each chicken breast. About 3 on each breast should work fine. Layer mozzarella, sliced tomato, and basil leaf into each pocket. Place each breast onto a baking sheet lined with parchment and bake for 25 minutes, or until the chicken is fully cooked.
In a small sauce pan heat balsamic vinegar and sugar over medium high heat and bring to a boil. Once boiling, stir to dissolve sugar and reduce to a simmer for about 5 - 7 minutes. Make sure to keep and eye on it and stir occasionally. I burned my first batch and ended up with balsamic vinegar candy. You will know that the mixture is done when it coats the back of a spoon and makes a thick drizzle. Pour balsamic vinegar reduction over the chicken and serve immediately.