On a plate, sprinkle salt on zucchini slices and let sit for 10 minutes to release excess moisture. Blot with paper towels and preheat broiler to high. Broil zucchini on a sheet pan until slightly browned and tender, about 2-3 minutes per side. Set aside.
Meanwhile make the tomato sauce by heat a large skillet over medium heat. Add olive oil, onion, and garlic and cook until translucent. Add chopped mushrooms and cook 5 minutes more. Pour in crushed tomatoes and dried basil and bring to a boil. Reduce heat to low and simmer, covered 30 minutes. Remove from heat and let cool.
In small bowl combine ricotta and egg.
In a 13x9-inch pan spread with 1/2 cup of sauce mixture. Layer a single layer of zucchini on top. Add 4 lasagna noodles and 1/3 of ricotta mixture. Top with 1 cup of mozzarella cheese. Repeat with remaining 2 layers, ending with mozzarella cheese.
Cover with plastic wrap and foil and cover tightly. Place in freezer.
To Bake: Preheat oven to 375ºF. Remove plastic wrap and foil and cover with a new sheet of foil. Bake 1 1/2 hours. Remove foil and cook until cheese is browned and bubbly, about 10 minutes more. Serve.