Preheat and prep: Heat your oven to 400°F (200°C). Line a baking sheet with parchment or lightly oil an oven-safe skillet.

Butterfly the chicken: Place a hand on top of each breast. Using a sharp knife, slice horizontally to create a pocket, stopping about 1/2 inch from the other side. Don’t cut all the way through.

Season generously: Pat the chicken dry. Sprinkle salt, pepper, garlic powder, onion powder, and Italian seasoning inside the pocket and over the outside of each breast. Drizzle with 1 tbsp olive oil and rub to coat.

Build the filling: Layer 2 slices of mozzarella, a small handful of basil leaves, and a few tomato halves inside each pocket. Avoid overfilling so the chicken closes easily.

Secure: Use 2–3 toothpicks along the seam of each breast to keep the filling inside. Press gently to seal.

Sear for color (optional but recommended): Heat the remaining 1 tbsp olive oil in a large oven-safe skillet over medium-high heat. Sear the chicken 2–3 minutes per side until golden. This step boosts flavor and texture.

Bake: Transfer the skillet to the oven (or move the chicken to your prepared baking sheet). Bake 12–18 minutes, depending on thickness, until the internal temperature reaches 165°F (74°C).

Rest and finish: Let the chicken rest 5 minutes. Drizzle with balsamic vinegar or glaze. Top with extra basil and a light sprinkle of salt if needed.

Serve: Slice each breast crosswise to show the melted mozzarella and tomatoes. Pair with a simple salad, sautéed greens, or zucchini noodles.