Choose a saucepan that can later contain the lentils and pasta with sufficient water to cook them. Put in 2 tablespoons olive oil, the chopped bacon, onion, garlic, celery, and parsley, and turn on the heat to medium. Cook, stirring and turning the ingredients over often, until the vegetables become deeply colored, about 15 minutes. Add the chopped tornato, stir to coat it well, and cook for a few minutes until the fat floats free of the tomato.

Add the lentils, turning them over 3 or 4 times to coat them well, then add enough water to cover by 1 inch. Adjust heat so that the liquid simmers gently, and cook until the lentils are tender, about 25 to 30 minutes. Whenever the water level falls below the 1 inch above the lentils you started with, replenish with as much water as needed.

Ahead-of-time note: You can make the soup up to this point several hours or even a day or two in advance. Reheat thoroughly, adding water if necessary, before proceeding with the next step.

Add salt and several grindings of pepper, put in the pasta, and turn up the heat to cook at a brisk boll. Add more water if necessary to cook the pasta. When the pasta is done - it should be tender, but firm to the bite - the consistency of the soup should be more on the dense than on the thin side.

Taste and correct for salt and pepper. Add the grated cheese and about 1 tbsp of olive oil, stir thoroughly, then take off heat and serve at once.