In 2 tablespoons of olive oil, fry the bacon with the celery, carrot, onion and garlic and fry until the onion is golden. Add the wine and reduce it briskly over a high flame by two-thirds. Lower the heat, add the tomatoes, and the parsley, marjoram, salt and pepper. Leave the sauce to cook gently for 45 minutes. Pass the sauce through a sieve and serve with salsicce marchigiane. This sauce is also good on pasta, in which case do not sieve it.