Peel the onion and scrape the carrot. Wash all vegetables, to remove any impurities (except for the onion) and cut in half.
Put the water in a large pot, add all the vegetables and cook for 30 minutes over low heat, with the lid to enhances the cooking of vegetables.
Once the cooking time, remove the vegetables. Add the salt and the pasta, leaving cook according to the time suggested in the package of pasta of your choice.
When cooked, add the oil. Sprinkle with grated Parmigiano and serve hot.