EGG PASTA: Combine the flour and the salt in a bowl, make a well in the middle, add the egg and the olive oil. Using your fingers, lightly and gradually work the egg into the flour so that it is completely distributed throughout. When it is well combined, press the mixture together to form a dough. Turn it out onto a counter and begin to work it together. If it is too dry, add drops of water, a few at a time, to moisten the dough and help it come together. Knead the dough for about 10 minutes, until it feels smooth and supple. Put it in a plastic bag or wrap it in plastic, and set it aside to rest at least half an hour, preferably an hour before rolling it out.
LASAGNE: Prepare the pasta dough and set it aside to rest. Grate or slice the cheese; then prepare the tomato sauce and spinach-cheese filling. Heat the oil in a wide skillet, add the onion, garlic and marjoram or oregano and saute until the onion is transparent and soft. Season with salt; then add the tomatoes and wine. Cook slowly until the sauce is thickened. If the tomatoes are overly tart, correct the acidity by adding a pinch or two of sugar. Once they are cooked, pass them through a food mill; then season to taste with a few drops of vinegar, freshly ground black pepper and more salt if needed.
SPINACH-CHEESE FILLING: Remove the stems from the spinach; discard any bruised or yellow leaves. Wash the spinach well in 2 changes of water. Roughly chop the leaves into small pieces about an inch square. In a wide pan, heat the oil and saute the onion for several minutes; then add half the garlic, the spinach leaves and a sprinkling of salt. Cook until the spinach is wilted; then remove it to a bowl and combine it with the ricotta, eggs, Parmesan, the remaining garlic and the parsley and lemon peel. Season to taste with salt, freshly ground pepper and a scraping or two of nutmeg.
BECHAMEL: Melt the butter in a saucepan, add the flour, and cook over low flame for 2-to-3 minutes, stirring continuously. Scald the milk in a separate pan, then pour it into the flour-butter mixture, whisking as you do so. Season with salt, pepper and a scraping of nutmeg and continue to cook the sauce for 15 minutes over low heat, giving an occasional stir. Roll the dough thin, and cut the final strips into pieces that will fit your baking pan. Bring a pot of water to a boil and add salt. Have ready a large bowl of cold water. Cook several pieces of dough at a time. Remove them when they rise to the surface, and put them in the cold water to cool; spread on a kitchen towel. Preheat the oven to 350F. Butter a 9-by-13-inch baking dish and spread half the bechamel over the bottom. Piece together several strips of the pasta so that they cover the bottom and hang over the edges of the baking dish. (Later they will be folded over the top, effectively sealing in the fillings.) Spread 1/2 the tomato sauce over this first layer of pasta and cover with 1/2 the mozzarella. Put down another layer of pasta and cover this with 1/2 the spinach-cheese filling. Continue with more pasta, tomato and mozzarella, pasta and spinach-cheese filling. Finish by laying 1-or-2 strips of pasta down the center and folding the overhanging edges over the top. Cover with the remaining bechamel sauce. Cover the lasagna with foil and bake for 20 minutes. Remove the foil and continue baking for another 15 minutes, or until the top is puffed and browned. Let the lasagne rest for a few minutes; then cut it into pieces and serve.
NOTE: Lasagne can also be made by using commercial fresh pasta sheets,