Prep the chicken: Pat the chicken breasts dry.
Using a sharp knife, cut a deep pocket in each breast by slicing horizontally through the thickest side, stopping about 1/2 inch from the edge. Don’t cut all the way through. Season the outside with salt, pepper, and a light sprinkle of Italian seasoning.
Make the filling: In a bowl, combine cream cheese, mozzarella, Parmesan, chopped sun-dried tomatoes, spinach, garlic, lemon zest, and a squeeze of lemon juice.
Add a pinch of salt, pepper, and a dash of smoked paprika if using. Stir until everything is evenly mixed and creamy.
Stuff the chicken: Spoon the filling evenly into each pocket. Use toothpicks to secure the opening so the filling stays inside while cooking.
Don’t overfill; a snug, even layer works best.
Preheat and heat the pan: Set your oven to 375°F (190°C). Heat a large oven-safe skillet over medium-high heat with 1–2 tablespoons olive oil.
Sear for color: Place the stuffed chicken in the hot skillet. Sear 2–3 minutes per side until golden.
Handle gently with tongs to avoid squeezing out the filling.
Finish in the oven: Transfer the skillet to the oven and bake 12–18 minutes, depending on thickness. The chicken is done when it reaches 165°F (74°C) in the thickest part.
Rest and slice: Let the chicken rest 5 minutes. Remove toothpicks.
Slice across the grain to reveal the filling and keep the chicken juicy.
Serve it up: Spoon any pan juices over the slices. Finish with a squeeze of lemon and a sprinkle of Parmesan. Serve with roasted vegetables, herbed rice, or a simple arugula salad.