Cook the pasta in salted water as usual, drain over a sieve and set aside. Cut the bacon and onion into cubes and fry in a pan with a little margarine, then add the noodles to the pan and fry a little (they should be lightly browned, tastes better!)
Finally, the grated cheese is spread over the fried noodles and the pan is closed with a lid until the cheese has run nicely.