01 - Set the oven temperature to 400°F.
02 - Carefully cut a pocket into the side of each chicken breast without slicing all the way through.
03 - Drizzle olive oil over the chicken breasts and season both sides evenly with salt, pepper, and dried Italian seasoning.
04 - Fill each pocket with 2 to 3 slices of mozzarella, several slices of tomato, and 4 basil leaves. Secure with toothpicks if necessary.
05 - Heat an oven-safe skillet over medium-high heat and sear each chicken breast for 2 to 3 minutes per side until golden brown.
06 - Transfer the skillet to the oven and bake for 18 to 22 minutes until the chicken is fully cooked and cheese is melted.
07 - In a small saucepan, combine balsamic vinegar and honey. Simmer over medium heat, stirring occasionally, until reduced by half and syrupy, about 8 to 10 minutes.
08 - Remove toothpicks from chicken breasts, drizzle with the balsamic glaze, and serve immediately.