01 - Preheat the oven to 400°F. Lightly grease a baking dish with cooking spray or a small amount of olive oil.
02 - Heat a skillet over medium heat. Add the fresh spinach and cook for 2-3 minutes, stirring occasionally, until wilted. Remove from heat and let cool slightly.
03 - In a mixing bowl, combine the cooked spinach, crumbled feta cheese, softened cream cheese, minced garlic, chopped dill, nutmeg, and 1/4 teaspoon black pepper. Mix thoroughly until all ingredients are well blended and creamy.
04 - Pat the chicken breasts dry with paper towels. Using a sharp knife, carefully cut a horizontal pocket into the side of each chicken breast, taking care not to slice completely through. Make the pocket as deep as possible while keeping the sides intact.
05 - Divide the spinach-feta mixture evenly among the four chicken breasts. Spoon the filling into each pocket, pressing gently to pack it in. Secure the openings with toothpicks if necessary to prevent filling from escaping during cooking.
06 - Brush the outside of each stuffed chicken breast with olive oil. Season evenly with salt, 1/2 teaspoon black pepper, and paprika, ensuring all surfaces are coated.
07 - Place the stuffed chicken breasts in the prepared baking dish, leaving space between each piece. Bake for 25-30 minutes, or until the chicken is completely cooked through and the internal temperature reaches 165°F when measured with a meat thermometer.
08 - Remove the baking dish from the oven and carefully take out any toothpicks. Let the chicken rest for 5 minutes to allow juices to redistribute. Serve warm, garnished with lemon wedges and fresh parsley if desired.