Place the chicken breasts on a cutting board. Using a sharp knife, cut slits across the chicken breast about ¾ of the way through being careful not to cut all the way through.
Depending on the size of your chicken breast, you're going to want around 6 to 8 slits per chicken breast.
Stuff each slit with a slice of mozzarella cheese, half a grape tomato and a basil leaf.
Place the chicken breasts in a baking dish that has been coated with non-stick baking spray.
Brush each chicken breast with olive oil.
Sprinkle each chicken breast with salt, pepper and Italian seasoning.
Bake in a preheated 400 degree oven for 30 minutes or until the internal temperature of the chicken reaches 165 degrees.
Notes
Note: The quantity for tomatoes, cheese and basil will depend on how many slits you make in the boneless chicken breasts.