Preheat your oven to 180°C (350°F).
Use a sharp knife to carefully slice into the thick side of each chicken breast, creating a pocket without cutting all the way through.
In a bowl, combine sun-dried tomatoes, shredded mozzarella, chopped basil, and minced garlic. Mix until well combined, creating a flavorful stuffing.
Stuff each chicken breast generously with the mixture, pressing gently so it stays inside, then secure with toothpicks to prevent spilling during cooking.
Heat a skillet over medium-high heat, add olive oil, and once shimmering, sear the chicken for about 3-4 minutes per side until golden brown and crispy.
Transfer the skillet to the preheated oven or move the chicken to an oven-safe dish, then bake for 20-25 minutes, or until the internal temperature reaches 74°C (165°F).
Remove the chicken from the oven and let it rest for about 5 minutes, allowing the juices to redistribute.
Carefully remove the toothpicks, then slice the chicken to reveal the melty cheese and colorful filling inside.
Serve hot with your favorite sides, such as roasted vegetables or a fresh salad, and enjoy the rich, flavorful bites.