Use a good tomato sauce: Homemade, or a classico sauce, or whatever. Heat it up. Add oregano, basil, salt & pepper, and make taste tasty.
Beat the egg in a bowl about yeah-big. Add the cottage cheese, and blend. Chop the spinach. Dump boiling water over spinach so it wilts, then strain. Combine with the cheese/egg mixture. Add some salt, pepper, and nutmeg if you're going for style points.
From bottom to top, in a 9x13 pan, build the lasagne thusly:
Bake at 375F for 45 minutes. Loosely cover with tin foil if it's getting to brown. Let stand 10 minutes before hacking into it.