Preheat oven to 400 degrees F.
To make the balsamic reduction, add balsamic vinegar and honey to a small saucepan over medium heat. Bring to a slight boil and reduce by half, about 6-8 minutes; set aside and let cool.
In a small bowl, combine Fiesta Italian season blend with salt and pepper, to taste.
Slice the chicken breasts diagonally about ¾ way through the meat. Leave about ¼ inch intact to hold cheese and tomato slices. Sprinkle spice mixture evenly over the breasts and with your fingers, work the mixture onto the cuts and both sides of the chicken.
Spray an 11 x 7-inch baking pan with Great Value cooking spray
Place chicken into the pan. Insert one slice of mozzarella cheese and 1 slice of tomato into slits on chicken. Drizzle ½ teaspoon olive oil over chicken and roast in the oven until the chicken is completely cooked through, reaching an internal temperature of 165 degrees F, about 25-30 minutes.
While chicken is cooking, combine chopped mozzarella with chopped tomato. Add 2 tablespoons chopped basil, pinch salt and pepper, and drizzle mixture with ½ teaspoon olive oil. Set aside until ready to plate.
Remove chicken from the oven when the cheese has melted completely and chicken is done.
Top with whole basil leaves and serve immediately, topped with mozzarella and tomatoes, drizzled with balsamic reduction and garnished with more basil, if desired.