Instructions

1. Peel and finely chop the onion and celery. Peel the carrot and cut it into slices.
   
2. Heat the oil in a pot. Sauté the onion, carrot, and celery over medium heat, stirring frequently, for 5 minutes.
   
3. Meanwhile, wash and roughly chop the tomatoes. Add the tomatoes to the pot and sauté for a few more minutes, stirring often.
   
4. Pour 1 liter of water into the pot, bring to a boil, and season with salt. Cover and simmer over low heat for 15 minutes.
   
5. After 15 minutes, add the pastina to the pot and cook until it’s tender.