Place the chicken breasts in a resealable plastic bag and pour in the Italian salad dressing. Add the Italian herb seasoning and chicken seasoning. Knead the bag to ensure the chicken is well-coated with the marinade, then squeeze out any excess air before sealing the bag. Refrigerate for 4 to 6 hours, allowing the flavors to meld.

Preheat your oven to a scorching 500 degrees F (260 degrees C).

In a large cast iron or ovenproof skillet, heat the canola oil over medium-high heat until a small droplet of water sizzles and pops upon contact. Remove the chicken breasts from the marinade, discarding the used marinade. Place the chicken breasts into the hot oil and sear for about 2 minutes on each side.

Transfer the skillet to the preheated oven and bake for approximately 12 minutes, or until the chicken is cooked through and the juices run clear. Top each chicken breast with a slice of fresh mozzarella cheese and a slice of tomato.

Return the skillet to the oven and continue baking for an additional 3 to 5 minutes, or until the cheese has melted. Move the chicken breasts to a serving platter, adorn each with a fresh basil leaf, and finish with a drizzle of balsamic vinegar. Serve immediately.