For four. Bring a large pan of water to the boil for the pasta. Cook as normal. Meanwhile sweat the onions in a little oil add the bacon and continue to cook until the bacon looks done. Then add the tomatoes and parsley and simmer while the pasta cooks. Drain pasta, and place in a deep dish, which can go under the grill. When the sauce is ready (a medium thick consistency) pour over the pasta and add half the grated cheese. Stir the whole together and level the top and sprinkle the other half of the cheese over the top. Place under the preheated grill until nice and golden brown (10 mins under my grill) Plonk the dish on the table and let them help themselves. This doesn't need anything with it and the quantities are infinitely variable to accommodate the number of people at table. This is a great way of feeding a large number for next to no cost.