Preheat your oven to 400°F (200°C).
Pound chicken breasts to even thickness. Drizzle with 1 tbsp olive oil, then season with Italian seasoning and salt.
In an oven-safe skillet, heat 1 tbsp olive oil over medium-high. Sear chicken smooth-side down for 4 minutes, flip and cook 3 more minutes.
Add sliced tomatoes and minced garlic to the skillet. Drizzle remaining 1 tbsp olive oil and balsamic vinegar over the chicken.
Transfer the skillet to the oven and bake for 15–25 minutes, until chicken reaches 165°F internal temperature.
Remove from oven, top each breast with mozzarella. Broil for 2–3 minutes until cheese is melted and bubbly.
Garnish with fresh basil and optional balsamic glaze. Serve immediately.