In a large skillet, heat the olive oil over medium heat. Once hot, add the minced garlic and sauté for about 1 minute, or until fragrant.
Add the chopped spinach to the skillet and cook, stirring occasionally, until wilted, about 3-4 minutes.
In a large mixing bowl, combine the shredded cooked chicken, wilted spinach, ricotta cheese, cream cheese, half of the shredded mozzarella cheese, Italian seasoning, and season with salt and pepper. Mix well until all ingredients are evenly incorporated.
Carefully fold in the cooked pasta and halved cherry tomatoes into the chicken and spinach mixture until well combined.
Transfer the mixture to a greased 9x13 inch baking dish, spreading it out evenly to ensure even cooking.
Top the casserole with the remaining shredded mozzarella cheese and the grated Parmesan cheese, distributing it evenly across the surface.
Cover the baking dish with aluminum foil to prevent over-browning and bake in the preheated oven for 25 minutes. After this time, remove the foil and continue to bake for an additional 15 minutes, or until the top is bubbly and golden.
Once done, remove the casserole from the oven and let it cool for about 5 minutes before serving.
Notes
Serve hot, garnished with freshly chopped herbs for added flavor.