Preparation
Cook the spaghetti al dente in salted water.
Cut the pancetta into small cubes.
Slice the red onion. Heat a little olive oil in a pan and sauté the red onion and diced pancetta until crisp. Then add the tomatocubes plus a spoonful of pasta cooking water.
Beat an egg in a bowl. Add two tablespoons Parmesan (or Pecorino) cheese and finely chopped parsley.
Drain the spaghetti and stir in the tomato sauce. Turn off the heat and now add the egg mixture to the pasta. Season everything with pepper from the mill.
Divide the pasta in two plates. Add a little Parmesan cheese before serving.