Steps
1. Preheat the oven to 375°F (190°C).
2. Cut a pocket into the side of the chicken breast.
3. Mix the mozzarella cheese, chopped spinach, salt, and pepper together.
4. Stuff the cheese and spinach mixture into the chicken breast pocket.
5. Heat olive oil in an oven-safe skillet over medium-high heat.
6. Sear the stuffed chicken breast for 2-3 minutes on each side.
7. Transfer the skillet to the preheated oven and bake for 20-25 minutes until the chicken is cooked through.
8. Serve hot and enjoy!