Wash spinach carefully and chop coarsely. You should have about 2 well-packed cups of chopped spinach. Chop the onion and saute it lightly in the olive oil with the minced garlic. Combine the Ricotta cheese, grated Romano, spinach, sauteed onion, beaten eggs, and mix well. Season the mixture with a little salt, plenty of fresh ground black pepper and some chopped parsley.
Grate the Mozzarella coarsely and cook the lasagne noodles until they are just al dente. Now you are ready to assemble the lasagne.
Butter a large, oblong baking dish, or two smaller square ones. Arrange a layer of lasagne noodles in the bottom, then spread on a layer of Ricotta cheese mixture, sprinkle that with Mozzarella, and cover it over smoothly with tomato sauce. Repeat these layers once or twice more, until everything is used up. Be sure to end with sauce on top, regardless of whatever is directly beneath it.
Cover the baking pan with aluminum foil, crimping the edges tightly. Bake the lasagne at 350 degrees for 40 minutes, take off the foil cover, and bake it another 10 to 15 minutes uncovered. Serve very hot, with herb bread or garlic toast, and follow it with a very green, very crisp salad.