Bring a large pot of lightly salted water to a boil. Add lasagne and cook for 8 to 10 minutes or until al dente; drain.
Roast potatoes in oven for about 1 hour. Split potatoes and scoop out middle; discard skins. Mix Cheddar cheese into potatoes. In a bowl, blend together cottage cheese, eggs, salt and pepper; set aside.
Layer lasagne in a 20x30cm baking dish. Spread cottage cheese mixture over pasta. Layer pasta again and spread potato and cheese mixture to cover pasta. Smooth top.
In a frypan, fry bacon until halfway cooked. Spread over top of dish. Sprinkle onions on top. Dot with margarine.
Lower oven temperature to 180 degrees C and bake for 45 minutes.