Slice the chicken fillets into thin slices and chop the mushrooms finely. Fry them separately in butter with pepper and salt. Set aside.
Let the spinach wilt in some butter with pepper, salt, and a pinch of nutmeg.
Put half of the sautéed spinach in a tall measuring cup, along with the cream, Parmesan cheese, garlic, pepper, salt, and nutmeg. Blend everything until smooth to make a sauce.
Layer in a baking dish with the fresh lasagna sheets, sautéed chicken, mushrooms, half of the sautéed spinach, and the spinach-Parmesan sauce.
Finish with grated Parmesan cheese.
Bake the lasagna for 25 minutes in a preheated oven at 180°C. Serve immediately.
Tips
Add additional vegetables such as zucchini or pepper for more variation. Use grated mozzarella on top for an extra cheesy crust.