In a medium bowl, whisk together the balsamic vinegar, honey, olive oil or avocado oil, minced garlic, Italian seasoning, and Dijon mustard. Season the mixture with kosher salt and fresh ground black pepper to taste. Once combined, set the sauce aside until ready to use.

In a separate bowl, combine the sliced grape tomatoes, mozzarella balls, and chopped fresh basil. Season the mixture with kosher salt and fresh ground black pepper to taste and gently toss to combine. Set this mixture aside for later use.

Preheat your oven to 400°F (200°C). Heat the avocado oil or other high-heat oil in a large oven-safe skillet over medium-high heat. While the oil heats, season the pounded chicken breasts on both sides with kosher salt and fresh ground black pepper to taste. Once the oil is shimmering, add the seasoned chicken to the skillet in a single layer. Sear for 1-2 minutes on each side or until lightly golden brown.

With the chicken still in the skillet, pour the reserved balsamic sauce (from Step 1) over the chicken breasts. Let the sauce quickly come to a simmer, and use a wooden spoon to scrape up any browned bits from the bottom of the pan. This step helps infuse the chicken with flavor and creates a delicious pan sauce. I like to make sure to scrape every bit off for extra depth in the sauce.

Immediately remove the skillet from the heat. Evenly distribute the tomato mozzarella mixture (from Step 2) over the chicken breasts. Transfer the skillet, uncovered, to the preheated oven. Bake for 18-23 minutes or until the chicken is cooked through and reaches an internal temperature of 165°F (74°C). Remove from the oven and let the dish rest for 5 minutes before serving. I always recommend letting the chicken rest—it keeps it juicy and flavorful!