Bring a large saucepan of water to the boil, add 2 teaspoons of salt and a dash of oil. Add in the spaghetti, stir, boil furiously until almost cooked—al dente—15 minutes approx. Meanwhile heat the tomato fondue, add the diced cooked ham or bacon and simmer for 3 or 4 minutes. As soon as the spaghetti is cooked, pour off all the water and drain well; toss in a little butter and season with freshly ground pepper. Pour into a wide, hot bowl or pasta dish, then pour over the tomato fondue. Sprinkle with herbs and grated cheese and serve immediately on very hot plates.