Preheat the oven to 375°F and grease a 9x13-inch baking dish.

Cook the lasagna noodles until just barely done, then lay them out separately so they do not stick.

Heat the olive oil in a large skillet over medium heat.

Add the diced onion and cook for 5–7 minutes, until soft and translucent.

Add the minced garlic and cook for 1–2 minutes.

Stir in the shredded chicken and cook just until warmed through.

Season the chicken mixture with salt and black pepper, then set aside.

In a bowl, mix the ricotta cheese, 1/2 cup Parmesan cheese, egg, basil, and parsley.

Season the ricotta mixture with salt and black pepper.

Spread a thin layer of béchamel or Alfredo sauce across the bottom of the prepared baking dish.

Lay 3 noodles over the sauce.

Spread half of the ricotta mixture over the noodles.

Add half of the chicken mixture, 1 cup mozzarella, and about one-third of the remaining sauce.

Repeat with 3 more noodles, the remaining ricotta, remaining chicken, 1 cup mozzarella, and another third of the sauce.

Top with the final 3 noodles, the remaining sauce, remaining mozzarella, and remaining 1/2 cup Parmesan.

Add a light dusting of fresh nutmeg if desired.

Cover tightly with foil and bake for 25 minutes.

Remove the foil and bake for another 10–15 minutes, until golden and bubbling.

Let the lasagna rest for 10 minutes before slicing.