Cover the bottom of a large pot with extra virgin olive oil.

Peel the onion and chop it finely with a knife, then add the onion into the pot and let it cook gently for about 5 minutes, stirring frequently. It has to softens but pay attention not overcook or burn it.

Stir in the finely chopped carrots and celery and cook for 10 minutes on low heat, stirring frequently with a wooden spoon.

In the meantime, deseed the tomatoes, cut them into quarters and add them into the pot.

Finally, add the salt and basil and cook over medium heat for 20 to 25 minutes, stirring often.

When the tomatoes are soft, turn off the heat and pour everything into a colander, collecting the remaining cooking water in a bowl.

Purée the tomatoes with a vegetable mill, using the finest sieve, and collect the beautiful sauce in a pot. If it gets difficult to turn the mill, you can add a few tablespoons of the set aside cooking water to help you.

Now check the pomarola: if it is still too liquid - it will depend on the tomatoes you chose - you can cook it again on high heath for about 5 minutes.

Now the pomarola is ready... cook the pasta!