Steam spinach until tender; press out excess moisture and chop coarsely.
Chop mushrooms and onions and mince garlic over medium-high heat until onions are tender; drain excess liquid and cool.
Mix ricotta cheese, 2/3 cup Parmesan, egg, salt, pepper, basil and oregano in large bowl. Add cooled spinach and mushroom-onion mixture and mix on low speed until just blended.
Cook lasagna according to package directions; rinse under cool water and drain thoroughly.
Place four lasagna strips in bottom of lightly oiled 9 x 13-inch pan, overlapping slightly. Top with 2 cups of spinach filling. Sprinkle with 1 1/2 cups shredded cheese and 1/3 cup Parmesan. Repeat layering two more times and top with remaining four lasagna strips. Spread 1 cup of marinara or tomato-cream sauce over top and cover tightly with foil.
Preheat oven to 350°s; F and bake, covered, for 1 hour. Remove from oven and keep warm at least 30 minutes before cutting. Top with extra Parmesan cheese. (Can be refrigerated a day in advance of baking if desired.)/p>
Submitted by: Recipe Group Member