Begin by preheating the oven to 350°F (175°C) and apply grease to a 9×13-inch baking dish.
In a skillet, heat olive oil over medium heat, sauté minced garlic until aromatic, then add shredded chicken, seasoning with salt, pepper, and Italian herbs. Cook for 2-3 minutes and set aside.
Spread a thin layer of Alfredo sauce in the baking dish and layer 3-4 cooked lasagna noodles on top. Add half of the chicken mixture, a layer of ricotta cheese, spinach (if using), mozzarella, and more Alfredo sauce. Repeat layers, finishing with Alfredo sauce and topping with remaining mozzarella and Parmesan.
Cover with foil and bake for 30 minutes, then remove the foil and bake for another 15-20 minutes until bubbly and golden. Let rest for 10 minutes, garnish with parsley, and serve warm.