– In a large pot of boiling salted water, cook the lasagna noodles according to the directions on the package. Drain the noodles, rinse with cold water to cool, and set aside.
– Heat the olive oil in a large skillet over medium heat. Add the onion, zucchini, mushrooms, and garlic and saute for about 5 minutes, stirring occasionally until slightly softened. Turned off the heat. Stir in the spinach, cover the skillet, and set aside to allow the spinach to wilt.