Fry the onions in margarine until translucent, then add the mushrooms. Season the mushrooms with plenty of salt and lightly pepper. When the mushrooms start to give off liquid, add the tomatoes to the pan and let them steep for a few minutes. Now add the cream and bring everything to the boil. Turn the heat down and season with oregano, thyme and lemon pepper. Season to taste and sprinkle the parsley over the dish before serving.
If pasta is served with it, add a ladle of the pasta water to the sauce.
Mix the pasta and sauce in a large bowl to prevent the pasta from sticking.