In a medium bowl, combine the chopped spinach, artichoke hearts, cream cheese, mozzarella cheese, Parmesan cheese, minced garlic, Italian seasoning, salt, and pepper. Mix well until all ingredients are evenly combined.
Carefully slice a pocket into each chicken breast, ensuring you do not cut all the way through.
Stuff each chicken breast with the spinach and artichoke mixture, securing with toothpicks if necessary.
In a large oven-safe skillet, heat olive oil over medium-high heat. Once hot, add the stuffed chicken breasts. Sear for about 3-4 minutes on each side until golden brown.
Transfer the skillet to the preheated oven and bake for 20-25 minutes, or until the chicken is cooked through (internal temperature should reach 165°F or 74°C).
Remove the chicken from the oven, let it rest for a few minutes, then remove any toothpicks.
Garnish with fresh parsley before serving.
Notes
Serve with roasted vegetables or a fresh salad for a balanced meal.