In a large skillet melt the butter over medium heat. Add the onion and garlic and cook for a couple minutes until the onion softens.
Stir in the mushrooms and season with salt, pepper, Italian seasoning and red pepper flakes. Cook for about 5 minutes until the mushroom cook down a bit and start to brown.
Sprinkle the flour over the mushrooms and stir. Stir in the chicken broth and milk. Add the mafalda pasta, stir and cook for about 8 to 10 minutes or until the pasta is cooked through. There should be enough liquid but if you find that the pasta is not cooked enough and all the liquid is gone, add a bit more chicken broth.
Stir in the ricotta and Parmesan cheese, then add the spinach and stir. Cook for another minute until the spinach cooks down.
Stir in the chicken and sprinkle with mozzarella cheese. Place the skillet under the broiler for a couple minutes to melt the cheese.
Garnish with chopped parsley and serve.
If you don't like mushrooms, zucchini would make a great substitute.
Mafalda pasta resemble mini, bite-sized lasagna sheets. If you can't find those, any small pasta shape such as penne, rotini, bowties, rigatoni, etc. would work well.
If you want to use lasagna sheets, this will make enough filling to do a small lasagna. First add a layer sauce on the bottom, then layer noodles, sauce, cheese, repeat.
If the pasta isn't cooked enough to your liking, add more chicken broth until the consistency is perfect.
Properly cool the lasagna before storing it, so that it will freeze and store evenly. It will stay fresh for 3 – 5 days in an airtight container in the fridge. Frozen lasagna will last for 2 – 3 months, just be sure to allow to thaw fully in the fridge before re heating.