1. Begin by butterflying the chicken breasts. To do this, slice each breast horizontally through the middle, stopping just before cutting them entirely in half. This will create a pocket for the filling. Once butterflied, sprinkle the outside of the chicken breasts with salt, pepper, and smoked paprika for seasoning. Set aside.

2. In a small bowl, mix together the cream cheese, Parmesan cheese, feta cheese, baby spinach, and sun-dried tomatoes. Stir until all the ingredients are well combined into a creamy and flavorful mixture.

3. Take each seasoned, butterflied chicken breast and stuff it with the prepared cheese and spinach mixture. Use toothpicks to secure the edges and hold the filling in place. It’s perfectly fine if some of the filling falls out; it will add extra flavor during cooking.

4. Place a skillet over medium heat and add butter to the pan. Once the butter is hot and starting to melt, add the stuffed chicken breasts to the skillet. Brown all sides of the chicken, carefully turning them to ensure even cooking. Continue to cook the chicken until it reaches an internal temperature of 165°F (75°C) to ensure it is fully cooked through.

5. Once the chicken breasts have reached the desired internal temperature, remove them from the skillet. Let them rest for a couple of minutes, then remove the toothpicks. Serve your stuffed chicken breasts hot, and enjoy the delicious combination of creamy filling and perfectly seasoned chicken!