1. Preheat oven to 325 degrees F. Grease a deep 9×13 inch baking pan.
  2. Slice zucchini lengthwise into thin slices. Pat dry with paper towel and sprinkle slices lightly with salt.
  3. To prepare the meat sauce, cook and stir ground beef and black pepper in a large skillet over medium-high heat for 5 minutes. Add green pepper, onion, and garlic and cook while stirring until meat is no longer pink. Stir in tomato paste, tomato sauce, red wine, basil, and oregano. Bring to a boil; reduce heat and simmer sauce for about 20 minutes, stirring frequently.
  4. In a separate mixing bowl, stir egg, ricotta, and parsley together until combined.
  5. Spread 1/2 of the meat sauce into the bottom of the greased baking pan. Then layer 1/2 the zucchini slices, 1/2 the ricotta mixture, all of the spinach and mushrooms, then 1/2 the mozzarella cheese. Repeat by layering the remaining meat sauce, zucchini slices, ricotta mixture, and mozzarella. Spread Parmesan cheese evenly over the top; cover with foil.
  6. Bake for 45 minutes. Remove foil; raise oven temperature to 350 degrees F (175 degrees C), and bake an additional 15 minutes. Let stand for 5 minutes before serving.