Prepare the Spinach Filling by mixing softened cream cheese, mozzarella cheese, grated Parmesan, and minced garlic with well-drained cooked spinach until fully blended.

Butterfly the chicken breasts horizontally to create a pocket without cutting all the way through.

Season both inside and outside of the chicken breasts with salt, pepper, paprika, and Italian herbs.

Stuff each chicken pocket with the spinach and cheese mixture, securing with toothpicks if necessary.

Sear the chicken in a skillet with olive oil or butter over medium-high heat for 3–4 minutes on each side.

Bake in a preheated oven at 375°F (190°C) for 15–20 minutes until cooked through.

Let rest for 3–5 minutes, then slice and serve.