Preheat the oven to 375°F (190°C).
Using a sharp knife, carefully cut a pocket into the side of each chicken breast without cutting all the way through.
In a medium bowl, combine chopped spinach, sun-dried tomatoes, minced garlic, and finely chopped onion.
Heat 1 tablespoon of olive oil in a skillet over medium heat. Add the spinach mixture and sauté for 2-3 minutes until the spinach is wilted and onions are softened. Remove from heat and let cool slightly.
Stuff each chicken breast pocket evenly with the spinach and sun-dried tomato mixture.
Secure the opening of each stuffed chicken breast with toothpicks to keep the filling inside.
Rub the outside of each chicken breast with the remaining 1 tablespoon of olive oil.
In a small bowl, mix the dried Italian seasoning, salt, black pepper, and paprika. Sprinkle this seasoning blend evenly over all sides of the chicken breasts.
Heat an oven-safe skillet over medium-high heat. Add the stuffed chicken breasts and sear for 3-4 minutes on each side until golden brown.
Pour the chicken broth into the skillet around the chicken breasts.
Transfer the skillet to the preheated oven and bake for 15-20 minutes, or until the chicken is cooked through and reaches an internal temperature of 165°F (74°C).
Remove the skillet from the oven and let the chicken rest for 5 minutes before serving. Remove toothpicks prior to serving.