Sautee chopped onions and mushrooms until tender. Steam chopped spinach until wilted (or use thawed frozen spinach). Combine ricotta, mozzarella, 0.75 cup of the Parmesan, eggs, parsley, spices. Add spinach and 0.75 of sautee to mixture. Fill uncooked manicotti shells; place filled shells in a single layer in a greased 13x9 baking pan. Add remaining sautee to spaghetti sauce. Cover manicotti with sauce. Sprinkle with remaining Parmesan. Bake at 180ÂșC for 35 minutes. This is probably my favorite Italian dish. Recipe By :