- In a pot of salted boiling water, cook the pasta until al dente. Rinse under cold running water and oil lightly. Set aside.
- In a large non-stick skillet, brown the onion in 15 ml (1 tablespoon) of oil. Add the garlic and cook for 1 minute. Add the spinach and cook, stirring constantly, for 1 to 2 minutes. Season with salt and pepper. Set aside in a bowl.
- In the same skillet, brown the chicken in the remaining oil while crumbling it up with the back of a fork. Season with salt and pepper. Set aside in a large bowl.
- In the same skillet, melt the butter. Add the flour and cook for 1 minute over medium heat, stirring constantly. Gradually add the milk with the nutmeg and bring to a boil, stirring with a whisk. Season with salt and pepper. Pour over the chicken.
- With the rack in the middle position, preheat the oven to 180 °C (350 ° F).
- In a 33 X 23-cm (13 X 9-inch) baking dish, spread a third of the chicken and bechamel mixture. Cover with a layer of noodles and add another third of the chicken and bechamel mixture. Cover with a layer of noodles. Layer with the spinach mixture. Sprinkle with the Parmesan cheese. Cover with a layer of noodles and add the remaining chicken and bechamel mixture. Sprinkle with the Swiss cheese.
- Bake for about 45 minutes. Finish cooking under the broiler for about 5 minutes. Let stand for 15 minutes before serving.
Once the lasagna is assembled, it can be refrigerated for up to three days or frozen.