1. Preheat your oven to 375°F (190°C). Grease a baking dish with butter to prevent sticking.
2. In a large skillet, heat olive oil over medium heat. Add the chicken pieces and season with salt and pepper. Cook until the chicken is browned on all sides, about 6-8 minutes.
3. Add minced garlic to the skillet and sauté for another minute until fragrant.
4. Stir in the fresh spinach and cook until wilted, about 2 minutes.
5. Reduce the heat to low and pour in the heavy cream and chicken broth, stirring to combine. Allow the mixture to simmer gently for 5 minutes.
6. Sprinkle in the Italian seasoning, then add half of the mozzarella and Parmesan cheeses. Stir until the cheese has melted into the sauce.
7. Transfer the mixture into the prepared baking dish. Top with the remaining mozzarella and Parmesan cheeses.
8. Bake in the preheated oven for 20-25 minutes, or until the cheese is bubbly and golden brown.
9. Let it cool slightly before serving, allowing the flavors to meld together beautifully.

Remember to taste as you go, a lesson from my abuela that ensures your dish is perfectly seasoned to your liking. Cooking is as much about instinct as it is about following instructions!