1. Preheat your oven to 375°F (190°C) and lightly grease a 9×13 inch baking dish.
2. In a large skillet, heat the olive oil over medium heat. Add the onion and garlic, sautéing until they are translucent.
3. Add your pre-cooked shredded chicken to the skillet, mixing it in with the onions and garlic. Warm through, then set aside.
4. In a medium bowl, combine ricotta cheese, 1/2 cup of Parmesan, the egg, fresh basil, and parsley. Season with salt and pepper to taste, mixing well.
5. Spread a thin layer of béchamel or Alfredo sauce over the bottom of the prepared baking dish.
6. Lay 3 lasagna noodles over the sauce, then spread half of the ricotta mixture over the noodles. Top with half of the chicken mixture, 1 cup of mozzarella, and a third of the remaining béchamel sauce.
7. Repeat layers, starting with the noodles, remaining ricotta mixture, remaining chicken mixture, another cup of mozzarella, and another third of the béchamel sauce.
8. Top the second layer of béchamel sauce with the final 3 noodles, the last third of the béchamel sauce, remaining mozzarella, and 1/2 cup of Parmesan. If using, sprinkle nutmeg over the top.
9. Cover the dish with foil and bake for 25 minutes. Remove the foil and bake for an additional 10-15 minutes, or until the top is bubbly and golden.
10. Let the lasagna stand for 10 minutes before cutting to allow the layers to set.
Variations & Tips:
