Steps
1. Preheat the oven to 375°F (190°C).
2. Butterfly the chicken breast by slicing it horizontally, but not all the way through.
3. Open up the chicken breast and season both sides with salt and pepper.
4. Place the tomato slices, mozzarella cheese, and basil leaves on one side of the chicken breast.
5. Fold the other side of the chicken breast over the filling and secure with toothpicks.
6. Heat olive oil in an oven-safe skillet over medium-high heat.
7. Carefully place the stuffed chicken breast in the skillet and sear for 2-3 minutes on each side, until golden brown.
8. Transfer the skillet to the preheated oven and bake for 15-20 minutes, or until the chicken is cooked through and the cheese is melted.
9. Remove the toothpicks, slice the stuffed chicken breast, and serve hot.