Preheat your oven to 375°F. Boil a large pot of salted water. Cook the lasagna noodles until they are al dente. Drain them well. Lay them flat on wax paper so they do not stick together.

In a medium bowl, combine the ricotta cheese and the egg. Add the chopped parsley and black pepper. Stir until the mixture is smooth and well combined. Set this bowl aside for the layering phase.

Melt the butter in a saucepan over medium heat. Add the minced garlic and cook for 1 minute. Pour in the heavy cream and simmer gently. Do not let it boil hard. Stir in the parmesan cheese.

Keep whisking the sauce until the cheese melts completely. Add the nutmeg, salt, and pepper. The sauce should be thick enough to coat a spoon. Remove it from the heat once it is smooth.

Put your shredded chicken and chopped spinach in a large bowl. Pour about half a cup of alfredo sauce over them. Toss everything together. This keeps the chicken moist while the lasagna bakes in the oven.

Spread a thin layer of alfredo sauce in the baking dish. Place 3 or 4 noodles on top of the sauce. Spread half of the ricotta mixture over the noodles. This creates a creamy base.

Add half of the chicken and spinach mixture over the ricotta. Sprinkle one cup of mozzarella cheese over the top. Drizzle a little more alfredo sauce to keep it juicy. Repeat with another layer.

Place the last set of noodles on top. Pour the remaining alfredo sauce over the entire dish. Make sure the noodles are fully covered. This prevents them from getting crunchy or dry in the oven.

Sprinkle the remaining mozzarella and parmesan cheese on top. Cover the dish tightly with aluminum foil. Bake for 20 minutes. Then, remove the foil and bake for another 20 minutes until bubbly.

Remove the lasagna from the oven. Let it sit for at least 15 minutes before slicing. This rest time is very important. It helps the layers set so they do not slide apart.