To prepare for making lasagna, preheat your oven to 350°F and grease a 9×13-inch baking dish with either butter or nonstick spray. Next, take a separate 9×13-inch pan or a similarly shaped shallow dish and arrange the uncooked lasagna noodles in it. Pour hot water over the noodles until they are submerged and set the pan aside to let the noodles soak while you move on to the next steps. Make sure to occasionally agitate the noodles with your hands to prevent them from sticking together.
Next, heat a large skillet over medium-high heat and add some butter, followed by chopped onion. Cook until the onion turns translucent, which should take about 10 minutes. Then, add minced garlic and cook for an additional 2 minutes. After that, stir in some spinach and cook it briefly until it wilts.
Now it's time to add the sauce ingredients. Pour in some heavy cream, add fresh basil, and season generously with salt and pepper. Bring the mixture to a simmer and stir in grated Parmesan cheese and ricotta cheese until they melt. Then, add some cooked chicken to the mixture and remove the skillet from the heat. If the mixture is too runny, you can simmer it for a few more minutes to thicken it up.
To assemble the lasagna, start by adding a spoonful of the Alfredo mixture to the bottom of the prepared baking dish and spread it out evenly. Then, arrange a layer of soaked noodles over the sauce. Next, add about one-third of the Alfredo mixture on top of the noodles, followed by one-third of the shredded mozzarella cheese. Repeat the layers until you have used up all of your ingredients, with mozzarella cheese being the top layer.
Cover the dish with foil and bake it in the oven for 45 minutes. Then, uncover the dish and broil it for 2-3 minutes to brown the cheese, if desired. Let the lasagna rest for 10 minutes before serving. You can sprinkle some fresh parsley on top for garnish, if you like. Enjoy your delicious homemade lasagna!