Brown the onion and the bacon in butter and oil in a large frying pan, then shut down. In the meantime boil the guitar spaghetti, apart whisk the eggs with pecorino cheese and fresh ground pepper. Drain spaghetti and skip all on a high flame in the pan with the bacon and add a bit of pecorino. Turn off the fire and add the whisked eggs with cream and stir all without rekindle the flame. Serve
