Cut the chicken breasts into slices. Fry them in a pan over medium-high heat with a small amount of oil for 3–4 minutes per side until golden. Layer in a baking dish.
In a saucepan over medium heat, combine the frozen spinach, processed herb cheese, and tomato paste. If using fresh garlic, finely mince the clove and add it; otherwise add garlic granules to taste. Heat for 4–5 minutes, stirring occasionally, until the spinach is thawed and the sauce is warm. Season with paprika, salt, and pepper to taste.
Spread the sauce over the chicken. Cut the mozzarella into thin slices and distribute evenly over the sauce.
Bake for 25–30 minutes, or until the chicken reaches 74°C (165°F) internally and the mozzarella is lightly golden brown.